RULES TO ADD (S) A (ES) TO VERBS (HE-SHE-IT):

Rule # 1: verbs einding by(ch-sh-s-o-x-z) ad(es):
Example: watch-watches
Kiss-kisses
Fix-fixes.

Rule#2: verbs ending by (y,i) and add (es):
-study-studies
-cry-cries
Fly-flies.

Rule # 3 verbs ending by (y) preceded by a vowel, and other ending as : b, d, e, g, k, l, m, n, p, r, t, w just add (s).
Absorb-absorbs
Arrive-arrives
Swing-swings
Buy-buys.