"He might have studied English since middle school."

"He might have studied English since middle school."

I think but I am not sure if he has studied English since middle school until now. So it affects the present.

"He might have studied English last week."

I think that he studied English last week, but I am not sure 100%. And it just utters what happened in the past.

I think that the form of "might have studied" in each sentence is the same but the intended meanings are different. Do you agree?

Thank you a million for your help.