has been serving vs had been served

[Yueehs]

Hi teacher,

Which one of these is correct?

1) He has been serving internship with us from 1 March to 31 March last year.
2) He had been served internship with us from 1 March to 31 March last year.
3) He has served internship with us from 1 March to 31 March last year.
4) He had served internship with us from 1 March to 31 March last year.

 

[Tarheel]

No. Say:

He served an internship with us for the month of March last year.

 

[emsr2d2]

In BrE, we also use "intern" as a verb. I would say "He interned with us for the whole of March 2021".