What are the Marfa Lights? Unless, as long as and in case for the future

Q: What does unless mean?

Unless means if … not : You won't see the lights unless the night is clear says the same as You won't see the lights if the night isn't clear. It names the one thing that can change the result. The B1 lesson What are the Marfa Lights? on edio.ai teaches it beside as long as and in case , on a night of waiting for lights in West Texas.

Q: What does as long as mean?

As a condition, as long as means only if : something is fine on one condition. You can stay as long as you're quiet. Darius can have tacos as long as they see a light first. Like unless , it takes the present simple for the future: We'll go as long as the sky is clear , not as long as it will be clear . What are the Marfa Lights? uses it only in this sense.

Q: Which tense comes after unless, as long as and in case?

The present simple, even about tomorrow : Take a jacket in case it gets cold. We won't leave unless it gets too cold. Will , can or an order goes in the other half of the sentence. So it's in case it gets cold , not in case it will get cold , and as long as you stay quiet , not as long as you will stay quiet . He , she and it still take -s: in case he gets hungry .

Q: What's the difference between in case and if?

In case means doing something now because it might be needed ; if means you wait and act only when it happens. I'll take my jacket in case it gets cold : I take it now, and maybe it gets cold, maybe not. I'll put on my jacket if it gets cold : I wait and see. Both are correct, with different meanings. A compare block in What are the Marfa Lights? on edio.ai sets the two side by side.

Q: Is it "unless you hurry" or "unless you don't hurry"?

It's unless you hurry : the not is already inside unless . Unless you hurry, you'll miss the sunset means If you don't hurry, you'll miss the sunset. A second not flips the meaning, so unless the sky isn't dark is a mistake too. With if , keep the not : You won't see them if the sky isn't dark. The drills in What are the Marfa Lights? catch this double negative.

Q: What are the Marfa Lights?

The Marfa Lights are glowing lights seen on clear nights near Marfa, Texas . Visitors watch for them from a roadside viewing area nine miles east of town, on U.S. 90, looking toward the Chinati Mountains. People describe lights that twinkle, sometimes look colored, move, split apart, join, disappear and come back. Jade's feature in the B1 lesson What are the Marfa Lights? on edio.ai separates what has been tested from what nobody knows.

Q: Have the Marfa Lights been explained?

Partly, in one student test . In May 2004, physics students from UT Dallas spent four days recording with video cameras, binoculars, traffic counters and chase cars. The number of lights followed the traffic on U.S. 67, and a parked car's flashed headlights looked like a Marfa light from the viewing area. They concluded that the lights they saw came from headlights. Skeptics agree; others say some sightings are still unexplained, and Texas Parks and Wildlife says nobody really knows.

Q: How do I teach unless and in case to B1 students?

Start from a real plan with real risks , like a night trip: what could go wrong, and what should we pack? Take a jacket in case it gets cold. Then add a condition with unless and a permission with as long as . What are the Marfa Lights? on edio.ai moves from a feature and a night at a viewing area to the scheme, four self-checking drills and a trip-planning chat.

Q: What's a good game for practicing unless and in case?

Spin a wheel of sentence starters : each slice holds a prompt such as I never go on a trip without … in case … or I won't stay up late tonight unless … , and whoever spins finishes it aloud. In What are the Marfa Lights? on edio.ai, the wheel also asks what to pack for the viewing area and what the lights might be. For a twist, a pair plans a trip and the class adds one more in case .

Q: What's good homework for unless, as long as and in case?

Good homework mixes form drills with questions about meaning : gaps that need the present simple ( Take my sweater in case your sister … (feel) cold. ) and a quiz on which sentence means take snacks now, just to be safe . All ten homework tasks in What are the Marfa Lights? on edio.ai check themselves, ending with Jade's tips for the viewing area and the hosts' answer to a listener.

This B1 ESL lesson plan teaches unless, as long as and in case through the Marfa Lights, glowing lights in the West Texas desert.

Grammar: Unless (= if … not), as long as (= only if) and in case (= because something might happen), each with the present simple for the future: Take a jacket in case it gets cold.
Topic: The Marfa Lights, seen from a roadside viewing area, and a 2004 student test of the headlight idea, with words such as flicker, skeptic and dusk.
Activities: Jade's feature, a night at the viewing area and a listener's message, self-checking drills, a trip-planning chat and a wheel of speaking prompts.

What's inside

Chapter 1Strange lights, dark skies
- PictureUnlock
- Open a box and answer: lights and mysteriesOpen the boxUnlock
- Study the words: a night of mystery lightsVocabularyTry it
- Look at the pictures and chooseChoose by pictureUnlock
Chapter 2Let's read: lights in the desert
- Look at the photo: the desert near Marfa, TexasPictureUnlock
- Read the feature: what are the Marfa Lights?ArticleUnlock
- Read and mark true or falseTrue or falseUnlock
- Read again and choose the right answerQuizUnlock
Chapter 3Live from the viewing area!
- Listen to Jade and Darius at the viewing areaListeningTry it
- Transcript, for the teacherUnlock
- Listen and choose the right answerQuizUnlock
- Listen to the Listener's Take: Sergio from TexasListeningUnlock
- Transcript, for the teacherUnlock
- Listen and mark true or falseTrue or falseUnlock
Chapter 4Grammar: unless it's clear, in case it's cold
- Study the scheme: unless, as long as, in caseGrammar schemeTry it
- Choose the correct option: unless, as long as or in caseChoose the optionUnlock
- Fill in the gaps: use the present simpleFill in the gapsTry it
- Fill in the table: the present simple after in case, as long as and unlessFill in the tableUnlock
- Choose the correct answerQuizUnlock
Chapter 5Let's talk: a night trip
- Choose the right replies: plan a night tripChatTry it
- Spin the wheel and answer: unless, as long as, in caseSpin the wheelUnlock
Chapter 6Homework
- Match the words and the meaningsMatchUnlock
- Unscramble the wordsAnagramUnlock
- Fill in the gaps with the lesson's wordsFill in the gapsUnlock
- Find the matching pairs: two halves of a sentenceMemory gameUnlock
- Choose the correct optionChoose the optionUnlock
- Fill in the gaps: use the present simpleFill in the gapsUnlock
- Put the words in the correct orderUnjumbleUnlock
- Choose the correct answer: what does it mean?QuizUnlock
- Drag the words into the gaps: Jade's tips for the viewing areaDrag and dropUnlock
- Choose the correct option: the hosts answer SergioChoose the optionUnlock

Vocabulary

12 words and phrases from the lesson, each with a picture and audio in edio.

+9 more with pictures and audio in the lessonMore words

headlights
explanation
skeptic
viewing area
proof
binoculars
mirage
sighting
dusk

Grammar: unless, as long as and in case

Unless, as long as and in case attach a condition or a reason to a plan, and all three take the present simple even when they look ahead. On a cold desert night spent waiting for lights, learners match each word to its meaning, use it with every person, keep in case apart from if and drop the extra will or not.

unless, as long as, in case

Three ways to talk about conditions and plans. After all three, use the present simple, even for the future.

Three words, three meanings

Unless means if … not: You won't see them unless the sky is dark. As long as means only if: You can stay as long as you're quiet. In case means something might happen: Take a jacket in case it gets cold.

What do they mean?

Word	It means	Example
unless	if … not	You won't see them unless the sky is dark. (= if the sky isn't dark)
as long as	only if	You can stay as long as you are quiet. (= only if you're quiet)
in case	because something might happen	Take a jacket in case it gets cold. (= maybe it gets cold later)

At the viewing area

You won't see the lights unless the night is clear.
We brought jackets in case it gets cold.
Darius can have tacos as long as they see a light first.
Darius is filming in case Riley wants proof.
We can't call it solved unless we know what every light is.
The lights are real, as long as you don't ask what they are!

The present simple, even for the future

After all three, a present verb carries the future meaning, with -s for he, she and it: in case he gets hungry, as long as she stays warm. Will, can or an order goes in the other part: We'll go as long as the sky is clear.

Every person: the present simple

Who	unless	as long as	in case
I	unless I feel tired	as long as I stay warm	in case I get hungry
you	unless you feel tired	as long as you stay warm	in case you get hungry
he	unless he feels tired	as long as he stays warm	in case he gets hungry
she	unless she feels tired	as long as she stays warm	in case she gets hungry
it (the dog)	unless it feels tired	as long as it stays warm	in case it gets hungry
we	unless we feel tired	as long as we stay warm	in case we get hungry
they	unless they feel tired	as long as they stay warm	in case they get hungry

No will after them

Use the present simple after unless, as long as and in case, even for the future. Put will, can or an order in the other part: We'll go as long as the sky is clear. Not: as long as it will be clear. Take a jacket in case it gets cold. Not: in case it will get cold.

If or in case?

Both are good grammar, but the meaning differs. I'll put on my jacket if it gets cold: I wait, and only then do I act. I'll take my jacket in case it gets cold: I act before, just to be safe, and maybe it never gets cold.

if = only when it happens

I'll put on my jacket if it gets cold. (I wait. Is it cold? Then I put it on.)
We'll go home if it rains.

in case = before, just to be safe

I'll take my jacket in case it gets cold. (I take it now. Maybe it gets cold, maybe not.)
We'll take an umbrella in case it rains.

Unless already means not

Unless carries the not inside it, so a second not turns the meaning around: Unless you hurry, you'll miss the sunset, not Unless you don't hurry. With if, the not stays: You won't see them if the sky isn't dark.

unless already means “not”

Unless = if … not, so don't add another not: You won't see them unless the sky is dark. ✅ Not: unless the sky isn't dark. With if, you need the not: You won't see them if the sky isn't dark. ✅

Common mistakes

You won't see them unless the sky isn't dark.
You won't see them unless the sky is dark.
unless already means if … not
Take a jacket in case it will get cold.
Take a jacket in case it gets cold.
in case + present simple
You can come as long as you will stay quiet.
You can come as long as you stay quiet.
as long as + present simple
Unless you don't hurry, you'll miss the sunset.
Unless you hurry, you'll miss the sunset.
one not is enough

More lessons on this grammar: Zero and first conditional lessons and exercises

Try the unless and in case exercises

Try them yourself: these are the same exercises your students do in edio.

What's in the lesson

17 auto-checked exercises
5 games
1 article
1 grammar scheme
1 set of word cards
2 audio clips
2 pictures
2 transcripts

The main objectives of this lesson are to:

say what must happen first with unless: You won't see the lights unless the night is clear. Riley won't believe it unless Darius sends her a video.
set a condition with as long as: You can sit with us as long as you keep your phone light off.
explain a precaution with in case: Darius is filming in case Riley wants proof. Bring binoculars in case a light flickers far away.
tell in case from if: I'll take my jacket in case it gets cold (now, to be safe), but I'll put on my jacket if it gets cold (later)
leave out will and a second not: Unless you hurry, you'll miss the sunset, not Unless you don't hurry or unless you will hurry

Lesson 32 closes Mysteries and lost worlds, unit 8, and with it English B1.1 · Stories That Travel. It goes one step past the first conditional of A2.2 lesson 15 and reuses the rule of B1.1 lesson 11, where when and as soon as took a present verb for the future. English B1.2 · Changemakers opens with the second conditional. A night of waiting for lights that may not come calls for plans against cold and clouds, the work these three words do.

Students open boxes of questions about strange lights, night skies and packing, then learn twelve words, from flicker and bundle up to sighting and dusk, with pictures and audio. They read Jade's feature on the lights and the 2004 headlight test, then hear Jade and Darius wait for the lights on a clear, cold night and Sergio, a listener from Texas, share his theory, both AI-voiced. The grammar chapter has the scheme and four self-checking drills, among them a table of all seven persons after the three words. In the speaking chapter, students plan a night trip with Jade in a chat, then spin a wheel of prompts to answer aloud.

All ten homework tasks check themselves: four for the words, among them a memory game of sentence halves, then a choice of forms, present simple gaps, word order, a quiz on meaning, Jade's viewing-area tips with words to drag in and the hosts' answer to Sergio.

Grammar:: unless · as long as · in case · present simple for the future
Topic:: the Marfa Lights · Marfa, Texas · West Texas · mysteries · night trips · skeptics · Stories That Travel

Teaching tips

Pack a bag on the board before the grammar: students call out what they'd take on a night trip to the desert, and you write each reason with in case: a blanket in case the wind gets stronger.
After the feature, split the board in two: what the 2004 students tested and concluded, and what nobody knows yet. Students sort sentences from the text, which keeps a test result from turning into a final answer.
Turn if … not into unless aloud: read If the sky isn't clear, we won't see the lights and let a student rewrite it. The class checks that only one not is left.
Borrow Sergio's joke as a model: The lights are real, as long as you don't ask what they are! Each student writes a funny rule of their own with as long as about school, home or a pet.

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The whole course: English B1.1 · Stories That Travel

32 lessons for adults at B1 in American English, each built around a true story. Riley, Jade and Darius make a podcast in Kansas City about true American stories, and each lesson tells one, from a seaplane airport in Alaska to the Marfa Lights of West Texas. Learners compare the present perfect with the past simple, use future forms, modals and quantifiers, and give their own opinions. The practice exercises check themselves.See the course

Unit 1 Travel smart
the present perfect vs the past simple, for and since, indirect questions, be used to and get used to
Unit 2 Dream jobs, new jobs
will have to and won't be allowed to, the present perfect continuous, simple vs continuous, would vs used to
Unit 3 Space and discovery
it's + adjective + to, What's it like to…?, future forms compared, future time clauses, too and enough + to
Unit 4 Life online
the more…, the more…, be supposed to, ought to and had better, let, make and allow
Unit 5 Screen and page
-ed and -ing adjectives, gradable and extreme adjectives, present tenses for a plot, articles for things in general
Unit 6 Green living
few and a few, little and a little, all, most, some and none, each and every, fewer and less
Unit 7 Sporting moments
could, was able to and managed to, for, during and while, present tenses for live commentary, question tags
Unit 8 Mysteries and lost worlds
both… and, either… or and neither… nor, uncountable nouns, how sure we are about the future, unless, as long as and in case
1. Lesson 29A calendar made of posts?Both… and, either… or, neither… nor
2. Lesson 30What was the Great House for?Uncountable abstract nouns
3. Lesson 31What does Newspaper Rock say?Certainty about the future
4. Lesson 32 · you're hereWhat are the Marfa Lights?Unless, as long as and in case

Questions about this lesson

What does unless mean?

Unless means if … not: You won't see the lights unless the night is clear says the same as You won't see the lights if the night isn't clear. It names the one thing that can change the result. The B1 lesson What are the Marfa Lights? on edio.ai teaches it beside as long as and in case, on a night of waiting for lights in West Texas.

What does as long as mean?

As a condition, as long as means only if: something is fine on one condition. You can stay as long as you're quiet. Darius can have tacos as long as they see a light first. Like unless, it takes the present simple for the future: We'll go as long as the sky is clear, not as long as it will be clear. What are the Marfa Lights? uses it only in this sense.

Which tense comes after unless, as long as and in case?

The present simple, even about tomorrow: Take a jacket in case it gets cold. We won't leave unless it gets too cold. Will, can or an order goes in the other half of the sentence. So it's in case it gets cold, not in case it will get cold, and as long as you stay quiet, not as long as you will stay quiet. He, she and it still take -s: in case he gets hungry.

What's the difference between in case and if?

In case means doing something now because it might be needed; if means you wait and act only when it happens. I'll take my jacket in case it gets cold: I take it now, and maybe it gets cold, maybe not. I'll put on my jacket if it gets cold: I wait and see. Both are correct, with different meanings. A compare block in What are the Marfa Lights? on edio.ai sets the two side by side.

Is it "unless you hurry" or "unless you don't hurry"?

It's unless you hurry: the not is already inside unless. Unless you hurry, you'll miss the sunset means If you don't hurry, you'll miss the sunset. A second not flips the meaning, so unless the sky isn't dark is a mistake too. With if, keep the not: You won't see them if the sky isn't dark. The drills in What are the Marfa Lights? catch this double negative.

What are the Marfa Lights?

The Marfa Lights are glowing lights seen on clear nights near Marfa, Texas. Visitors watch for them from a roadside viewing area nine miles east of town, on U.S. 90, looking toward the Chinati Mountains. People describe lights that twinkle, sometimes look colored, move, split apart, join, disappear and come back. Jade's feature in the B1 lesson What are the Marfa Lights? on edio.ai separates what has been tested from what nobody knows.

Have the Marfa Lights been explained?

Partly, in one student test. In May 2004, physics students from UT Dallas spent four days recording with video cameras, binoculars, traffic counters and chase cars. The number of lights followed the traffic on U.S. 67, and a parked car's flashed headlights looked like a Marfa light from the viewing area. They concluded that the lights they saw came from headlights. Skeptics agree; others say some sightings are still unexplained, and Texas Parks and Wildlife says nobody really knows.

How do I teach unless and in case to B1 students?

Start from a real plan with real risks, like a night trip: what could go wrong, and what should we pack? Take a jacket in case it gets cold. Then add a condition with unless and a permission with as long as. What are the Marfa Lights? on edio.ai moves from a feature and a night at a viewing area to the scheme, four self-checking drills and a trip-planning chat.

What's a good game for practicing unless and in case?

Spin a wheel of sentence starters: each slice holds a prompt such as I never go on a trip without … in case … or I won't stay up late tonight unless …, and whoever spins finishes it aloud. In What are the Marfa Lights? on edio.ai, the wheel also asks what to pack for the viewing area and what the lights might be. For a twist, a pair plans a trip and the class adds one more in case.

What's good homework for unless, as long as and in case?

Good homework mixes form drills with questions about meaning: gaps that need the present simple (Take my sweater in case your sister … (feel) cold.) and a quiz on which sentence means take snacks now, just to be safe. All ten homework tasks in What are the Marfa Lights? on edio.ai check themselves, ending with Jade's tips for the viewing area and the hosts' answer to a listener.

How do you practice unless and in case one-to-one?

Plan a trip together and pack the bag aloud: the teacher names a place, the student says what to take and why with in case, then sets a rule with as long as. The chat in What are the Marfa Lights? on edio.ai needs no partner: Jade invites the student to the viewing area, and each wrong reply breaks the verb after the three words, as in in case it will be cloudy.

Are there interactive exercises for unless and in case?

Yes: a gap-fill and a chat that check answers at once. Without an account, this page plays three parts of What are the Marfa Lights?, a B1 lesson on edio.ai: Jade and Darius at the viewing area, a gap-fill with the present simple after the three words, and the night-trip chat with Jade. The word cards and the grammar scheme are on the page as well, and an account opens everything else.

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About this lesson

What's inside

Vocabulary

Grammar: unless, as long as and in case

Three words, three meanings

What do they mean?

At the viewing area

The present simple, even for the future

Every person: the present simple

If or in case?

Unless already means not

Common mistakes

Try the unless and in case exercises

What's in the lesson

The main objectives of this lesson are to:

Teaching tips

Teach the whole lesson in edio

Start a free trial

Open the lesson

Teach it live or as homework

The whole course: English B1.1 · Stories That Travel

Unit 1 Travel smart

Unit 2 Dream jobs, new jobs

Unit 3 Space and discovery

Unit 4 Life online

Unit 5 Screen and page

Unit 6 Green living

Unit 7 Sporting moments

Unit 8 Mysteries and lost worlds

Questions about this lesson

Teach this lesson with your students