Unit 7A: Ups and Downs

Language Focus

Grammar rules

Must and Can't

We use must and can't to comment on what we are hearing and to express how certain we are about an idea.

Meaning

Modal	Meaning
must + verb	the idea in our comment is very likely
can't + verb	the idea in our comment is very unlikely

Form

Time	Form	Example
Present	must / can't + infinitive (without to)	That must get* awkward.* / It can't be* easy.*
Past	must / can't + have + past participle	That must've been* nice.* / That can't have been* much fun.*

Key points

must suggests we think something is probably true: Wow! That must've been nice.
can't suggests we think something is probably not true: It can't be easy.
We generally don't respond to these comments as if they were questions.
We don't usually repeat the modal verb in the comment — instead, we say something about the real situation.

GRAMMAR WORKSHEET: ADDING COMMENTS USING MUST & CAN'T

PART 1: Complete the Comment with MUST or CAN'T (Present or Past)

Directions: Write must or can't followed by the correct form of the verb in parentheses (present: verb | past: have + past participle).

1. A: "She works 12 hours a day and goes to the gym every night."
B: "Wow, that _______________________ (be) easy for her."

2. A: "I lost my phone and wallet on the subway yesterday."
B: "Oh no, that _______________________ (be) terrible!"

3. A: "Look at the snow outside! The highway is completely blocked."
B: "It _______________________ (be) impossible to drive right now."

4. A: "They just won a fully funded trip to Europe!"
B: "They _______________________ (be) so excited!"

5. A: "He passed the advanced test without studying a single minute."
B: "It _______________________ (be) a very difficult exam, then!"

6. A: "We waited in line for 3 hours, but we didn't get tickets."
B: "That _______________________ (get) really frustrating."

PART 2: Choose the Natural Conversational Response

Directions: Circle the best response. Remember to respond to the real situation, not repeat the modal verb!

7. A: "That must have been a scary experience!"
B: a) Yes, it must. b) Yes, it was. c) No, it couldn't.

8. A: "It can't be easy balancing work and school."
B: a) No, it isn't. b) No, it can't. c) Yes, it must.

9. A: "You must be thrilled about your new job!"
B: a) Yes, I must. b) Yes, I am! c) No, I can't.

10. A: "That must have cost a fortune!"
B: a) Yes, it did! b) Yes, it must. c) No, I haven't

Word / Phrase	Meaning
complete a doctorate	finish a PhD (the highest university degree)
trial separation	a period when a married couple live apart to decide if they want to stay together
falling-out	a serious argument that ends a relationship or friendship
pass away	to die (a more polite way of saying it)
make a clean break	to leave a situation completely and start fresh
move away	to go to live in a different place
golden anniversary	the 50th wedding anniversary
tie the knot	to get married
fly the nest	to leave your parents' home to live independently
premature	born before the expected time (for a baby)

We often don't hear the /t/ in must and can't when we speak quickly.

Sentence	Phonetic transcription
1. You must find that quite tough.	/juː mʌs faɪnd ðæt kwaɪt tʌf/
2. That must get pretty dull on occasion.	/ðæt məs get ˈprɪti dʌl ɒn əˈkeɪʒn/
3. That must've been fascinating.	/ðæt ˈmʌstəv biːn ˈfæsɪneɪtɪŋ/
4. I guess that can't be avoided.	/aɪ ɡes ðæt kɑːnt biː əˈvɔɪdɪd/
5. You can't be very happy about that.	/juː kɑːnt biː ˈveri ˈhæpi əˈbaʊt ðæt/