Directions: Choose the appropriate modal to complete the sentence. Her mother…

Solution

Correct answer: couldn't.

Explanation:

• Meaning of "couldn't": expresses inability or lack of ability in the past (was not able to).

• Why it fits: the sentence uses a past context ("Her mother was away"), which explains why she was unable to give advice; therefore "couldn't advise her" is appropriate.

• Why the other modals are not suitable:

  • "shouldn't": expresses advice or that something is not recommended, not past inability.

  • "needn't": indicates lack of necessity (no obligation), not inability.

  • "can't": denotes present inability or impossibility; the context here is past, so the past form "couldn't" is required.

Correct sentence: Her mother was away and couldn't advise her.