Question

Why aliphatic amines are stronger bases than aromatic amines

Answer 1

in aromatic amine, lone pair is conjugated with aromatic ring, so it's hard to lose electrons. so it's less basic

Answer 2

The basicity of amines is due to the nitrogen of the amine donating its lonepair of electrons. In aromatic amines this lone pair is in conjugation(delocalized) with the aromatic ring. While in aliphatic mine this dosent happen and thus the lone pair is ready to be donated.