donates an electron pair to an electrophile to form a chemical bond

all molecules or ions with a free pair of electrons or at least one pi bond can act as nucleophiles

nucleophile are Lewis acids by definition

a nucleophile becomes attracted to a full or partial positive charge

Electrophiles are positively charged or neutral species having vacant orbitals

The electrophiles are attacked by the most electron-populated part of one nucleophile

Electrophiles are Lewis base

CH₃NH_2

(CH₃)_2NH

(CH₃)₃N

(CH₃)₄N⁺