Expressing Uncertainty in English

What is the primary phrase introduced to express uncertainty in English?

• I am unsure

• I don't know

• I might not

• I can't tell

Which of the following is NOT a correct use of 'I don't know' with a tense?

• I don't know who is going to the party.

• I don't know who will have gone to the party.

• I don't know who went to the party.

• I don't know who usually goes to the party.

What is a stative verb?

• A verb that describes an action

• A verb that can be used in continuous form

• A verb that is always in past tense

• A verb that describes a state or condition

Which of the following sentences is incorrect?

• I don't know whether Jane has arrived.

• I don't know if I locked the door.

• I am not knowing if I locked the door.

• I didn't know if I locked the door.

Why should 'know' not be used in continuous form?

• Because it is a stative verb

• Because it is an action verb

• Because it is always in past tense

• Because it is a future tense verb