CBSE Class 12 · 2002 · Delhi Compartment · Compounds Containing NitrogenVery Short Answer

Methylamine: the +I methyl pushes electron density onto nitrogen → lone pair readily protonated.
Aniline: the lone pair conjugates with the ring, and the anilinium ion loses that resonance — protonation is resisted.
Hence \textbf{CH${}_3$NH${}_2$ ≫ C${}_6$H${}_5$NH${}_2$} in basicity (K${}_b$ 4.4×10${}^{-4}$ vs 4.2×10${}^{-10}$).