Answer
Carbon forms 4 bonds to have a formal charge of 0. Carbon here has 3 bonds and one lone pair, which gives it a formal charge of -1.
Work Step by Step
Formal Charge (FC) = [number of valence electrons] - [number of non-bonding electrons] - 1/2 [shared electrons]
FC (carbon) = 4-2-3 = -1
FC (hydrogen) = 1-0-1 = 0
