72 Modals in the Past: Could Have v3/Need Have v3

We use these Past Modal Verbs to talk about things that did not take place in past. It can be also used for possibilities that if something was different in the past.

• The structure for Could have + past participle is as follows: Subject + could + have + past participle;
• The structure for Couldn’t have + past participle is as follows: Subject + could + not + have + past participle;
• The structure for Need + not + have + past participle is follows: Subject + need + not + have + past participle.

• You could have bought a bouquet of flowers but you didn’t.
• They couldn’t have done anything for drought.
• You needn’t have fed the marine animals in the ocean.

There are some differences between Modals in the past:

• Could + have + past participle is used to talk about past actions that we didn’t carry out even if we were able to do;
• Couldn’t have + past participle is used to talk about actions that were impossible to do, even if we wanted to do them;
• Needn’t have + past participle is used to talk about actions that happened in the past, which were unnecessary or waste of time.