Unless exercises with answers

Quick answer. Unless means if … not: We will miss the bus unless we leave now = We will miss the bus if we do not leave now. In a real future condition, use a present form after unless, not will. Do not add another negative unless the meaning genuinely requires it.

Unless: meaning and sentence pattern

Unless introduces the condition that prevents or changes the result. The clause can come first or second. Use a comma when the unless-clause comes first: Unless it stops raining, we will stay home.

Exercise 1: choose the correct form

1. We will start without Mia unless she ___ soon. (arrives / will arrive)
2. Unless you ___ the file, nobody can read it. (attach / will attach)
3. I do not buy coffee unless I ___ very tired. (am / will be)
4. Unless the weather ___, the match will continue. (changes / will change)
5. He would not ask unless he ___ help. (needed / would need)
6. Unless they ___ us, we will use the original plan. (contact / will contact)

Unless and if not

In many real conditions, the two forms are equivalent. Compare them before rewriting: the negative belongs inside the if-clause but is already contained in unless. Practise the wider system on the conditionals exercises page.

Exercise 2: rewrite with unless

1. If you do not book today, the price may rise.
2. We cannot finish if Leo does not send the figures.
3. If the alarm does not ring, I will oversleep.
4. Do not call me if the problem is not urgent.
5. If she does not practise, she will not improve.
6. The dog does not bark if it is not frightened.

Do not create an accidental double negative

Unless you do not hurry, you will be late normally says the opposite of the intended meaning. Use Unless you hurry… or If you do not hurry…. A negative after unless is possible only when the negative itself is meaningful: Unless you do not want dessert, I will order two. Because that pattern is hard to process, an if-clause is usually clearer.

Exercise 3: correct the mistake

1. Unless you will leave now, you will miss the train.
2. I will not go unless Anna will come too.
3. Unless he does not apologise, I will forgive him.
4. We cannot enter unless we do not have a key.
5. Unless it will rain, we will have lunch outside.

When unless is not a safe replacement

Use if … not when the speaker is exploring alternatives rather than setting an exception: I wonder if he will not come cannot become an unless-clause. Also avoid automatic replacement in questions such as What happens if the machine does not start? The question asks about a possible event; it does not state a result with one exception.

Exercise 4: choose unless or if

1. I wonder ___ Maya will not recognise me.
2. We will cancel the picnic ___ the forecast improves.
3. What should I do ___ the password does not work?
4. Do not press this button ___ the engineer tells you to.
5. ___ you do not agree, explain your reason.
6. The room stays locked ___ a teacher is present.

Exercise 5: translate into English

1. Если ты не запишешь адрес, ты его забудешь.
2. Мы не начнём, если все не будут готовы.
3. Не открывай файл, если не знаешь отправителя.
4. Что делать, если автобус не придёт?
5. Если погода не изменится, мы останемся дома.

Typical mistakes for Russian-speaking learners

• Using will after unless in a real future condition.
• Keeping the negative from the original if … not sentence.
• Changing the result from positive to negative during a rewrite.
• Using unless in every sentence that contains Russian «если не».

Self-check and related practice

Continue with mixed tenses, modal verbs, question structure, relative clauses, purpose clauses and conjunctions.