Он уже пять месяцев заведует лабора

Он уже пять месяцев заведует лабораторией и многому научился за это время.

Results (English) 1:

He already has five months of laboratory and learned a lot during this time.

Results (English) 2:

He's already five months in charge of the lab and learned a lot during this time.

Results (English) 3:

It is already five months esiea laboratory and learned a lot during this time.