Why is it so It is because in
aniline or other arylamines, the -NH2 group is attached directly to
the benzene ring It results in the unshared electron pair on nitrogen
atom to be in conjugation with the benzene ring and thus making
it less available for protonation If you write different resonating
structures of aniline,  you will find that aniline is a resonance
hybrid of the following five structures