“…neque umquam rēctē respondet cum eum interrogāvī.”
“… and he never answers correctly when I asked him.”
It’s obviously me that’s wrong (it always is), but I can’t see where.
Paul.
PS: Notice I snuck the macrons in just to show off 
The Latin perfect is sometimes a true perfect, like the English “I have [done something],” rather than a simple past. In other words, interrogavi, for example, most often means “I asked,” but context will occasionally require that it be understood as “I have asked.” That seems to be the case here: “Nor does he ever answer correctly when I have asked him.” The perfect is used because the asking is prior to the answering; two presents (respondet, interrogo)would in Latin suggest that the asking and answering are simultaneous. English is less picky about temporal relationships.