modal verbs - Difference between (might, might have and could have)

Consider:

He might go to Beijing last month.

He might have gone to Beijing last month.

He could have gone to Beijing last month.

Any difference in meaning?

Answer

1.

He might go to Beijing.

Expresses a possible future action. Therefore the use of last month is impossible. You must use a time expression that goes with the future, for example:

He might go to Beijing next month.

2.

He might have gone to Beijing last month.

He could have gone to Beijing last month.

Both express a possible situation in the past.

→ He might have gone to Beijing last month.

According to context could mean:

• 
  

  There's a possibility he went to Beijing last month, I'm not sure perhaps he did something else.

  
  


• 
  

  I know he went some place last month, I don't exactly remember where, it could be Beijing. (sentence stress on "to Beijing" when spoken)

  
  


• 
  
  

  I know he went to Beijing sometime or other, it could be last month but I'm not sure. (sentence stress on "last month" when spoken)

  
  

→ He could have gone to Beijing last month.

There was a possibility for him to go to Beijing last month but he didn't go.