Underline the correct tense. 1 The plane leaves/has left at four o'clock. We must be
at the airport by two o'clock.
2 It gets/is getting colder and colder every day.
3 Have you seen Linda? I have been looking/am looking
for her for almost an hour.
4 Sam is a very interesting person. He knows/has known
all kinds of unusual facts.
5 First, you are heating/heat the oven to a temperature
of 180°C.
6 Have you heard the news? They have just elected!
have been electing a new club chairman!
7 Martha is finding/has found a new job. She is starting
next week.​

1. The correct tense in this sentence is "leaves". It is a future tense because it refers to a scheduled action that will happen in the future. The use of "must be" before the verb emphasizes the necessity of being at the airport by a certain time.

2. The correct tense in this sentence is "is getting". It is a present continuous tense because it describes an ongoing action of becoming colder and colder every day. The use of "every day" indicates a repeated action in the present.

3. The correct tense in this sentence can be either "have you seen" or "am looking". Both tenses are correct, but they convey slightly different meanings. "Have you seen" suggests that the action of looking for Linda happened in the past and is now completed, while "am looking" indicates that the action is still ongoing at the moment of speaking.

4. The correct tense in this sentence is "knows". It is a present simple tense because it describes a fact or a general truth about Sam. The use of "all kinds of unusual facts" indicates a habitual action or knowledge that Sam possesses.

5. The correct tense in this sentence is "heat". It is an imperative tense because it gives a command or instruction to heat the oven. The use of "to a temperature of 180°C" provides a specific instruction about the desired temperature.

6. The correct tense in this sentence is "have just elected". It is a present perfect tense because it describes an action that happened very recently, but its exact time is not specified. The use of "just" emphasizes the immediacy of the election.

7. The correct tense in this sentence is "has found". It is a present perfect tense because it describes a completed action that has an impact on the present. The use of "is starting next week" indicates that Martha's finding a new job has a direct consequence of her starting a new job in the near future.