"Lui insegna in questo liceo da tre anni."
There isn't any. But it's translated with an English past tense. http://italian.about.com/library/fare/blfare156a.htm
what age does a "liceo" cover - is it the equivalent to a secondary school in England (12-18)? Or is it a higher education college (16+ perhaps)? It would be helpful to have an alternative for non-American speakers.
I am totally baffled. Since when does insegna translate to has been teaching. This seems utterly incorrect