Understanding 'Must' and 'Must Not'

The video tutorial by Alisha covers the use of 'must' and 'must not' to express possibility in both present and past contexts. It explains how 'must' indicates a high probability, while 'must not' suggests a low probability. The lesson includes examples of using 'must be' with noun phrases, adjectives, and verbs in the '-ing' form for present possibilities, and 'must have been' for past possibilities. Negative forms like 'must not be' and 'must not have been' are used to express low or impossible chances. The tutorial concludes with a note on not using 'must' for future possibilities.

What is the main focus of the lesson introduced by Alisha?

• The use of 'must' and 'must not' for expressing permission.

• The use of 'must' and 'must not' for expressing certainty.

• The use of 'must' and 'must not' for expressing possibility.

• The use of 'must' and 'must not' for expressing obligation.

How is 'must be' used with noun phrases?

• To express doubt about something.

• To express a low chance of something being true.

• To express certainty about something.

• To express a high chance of something being true.

What does 'must be' plus an adjective indicate?

• A low chance of the adjective being true.

• A high chance of the adjective being true.

• Doubt about the adjective.

• Certainty about the adjective.

When using 'must be' with verbs in the '-ing' form, what is being expressed?

• Certainty about the action.

• A high chance of the action happening.

• A low chance of the action happening.

• Doubt about the action.

What does 'must not' express when used with noun phrases?

• Doubt about something.

• Certainty about something.

• A low chance of something being true.

• A high chance of something being true.

What is the pattern used for expressing past possibility with 'must'?

• 'Must not have been'

• 'Must not be'

• 'Must have been'

• 'Must be'

How is 'must have been' used with adjectives?

• To express a low chance of the adjective being true in the past.

• To express a high chance of the adjective being true in the past.

• To express certainty about the adjective in the past.

• To express doubt about the adjective in the past.

What does 'must not have been' indicate in past situations?

• A low chance of something being true in the past.

• A high chance of something being true in the past.

• Certainty about something in the past.

• Doubt about something in the past.

What is the significance of using 'must have' with verbs?

• To express certainty about an action in the past.

• To express a low chance of an action happening in the past.

• To express a high chance of an action happening in the past.

• To express doubt about an action in the past.

Why is 'must' not typically used for future possibility?

• Because it expresses certainty.

• Because it expresses doubt.

• Because it expresses obligation.

• Because other words like 'probably' are used.