$\underset{\mathrm{Acid}}{\underbrace{{\mathrm{H}}_2\mathrm{O}}}+\underset{\mathrm{Base}}{\underbrace{\ddot{\mathrm{N}}{\mathrm{H}}_3}}\to {}^{-}\mathrm{OH}+{\mathrm{NH}}_4^{+}$

$\underset{\mathrm{Base} }{\underbrace{{\mathrm{H}}_2\mathrm{O}}}+\underset{\mathrm{Acid}}{{\mathrm{H}}_2\mathrm{S}}⟶{\mathrm{H}}_3{\mathrm{O}}^{+}+{\mathrm{HS}}^{\ominus }$

The amphoteric behaviour of ${\mathrm{H}}_2\mathrm{O}$ is explained by Brønsted theory not the Lewis acid base theory.

So, we can say Assertion is false, but reason is true.