7 Complete the sentences with the correct form of a modal verb and the verbs in brackets. 1 Dave can't have left (not leave) yet - his coat is still here. 2 The traffic's really bad - I'm worried we (miss) our train 3 They're not at home. They (go) away for the weekend. 4 I can't find Jo. She (go) home. 5 The plane landed ten minutes ago. Bill (still/be) in baggage reclaim 6 Buy a laptop? With my pocket money? You (not be) serious!

1. Dave can't have left (not leave) yet - his coat is still here.
Explanation: We use "can't have" to express a strong deduction or certainty about something that happened in the past. In this case, we are deducing that Dave did not leave yet because his coat is still here.

2. The traffic's really bad - I'm worried we (miss) our train.
Explanation: Here, we use the modal verb "might" to express a possibility or uncertainty about missing the train due to the bad traffic. It indicates that there is a chance of missing the train.

3. They're not at home. They (go) away for the weekend.
Explanation: In this sentence, we use the modal verb "have" to express an action that happened in the past. It indicates that they went away for the weekend, which is why they are not at home now.

4. I can't find Jo. She (go) home.
Explanation: The modal verb "must" is used in this sentence to express a deduction or conclusion about Jo going home. It indicates a strong likelihood that Jo has gone home because she cannot be found elsewhere.

5. The plane landed ten minutes ago. Bill (still/be) in baggage reclaim.
Explanation: We use the modal verb "might" to express a possibility or uncertainty in this sentence. It suggests that there is a chance that Bill is still in baggage reclaim even though the plane has already landed.

6. Buy a laptop? With my pocket money? You (not be) serious!
Explanation: The modal verb "can't" is used here to express a strong impossibility or disbelief. It suggests that it is not possible for the person to buy a laptop with their pocket money, and questions the seriousness of the suggestion.