pat (someone) on the head

Translations
погладить (кого-то) по голове
He patted the child on the head and smiled.
Он погладил ребенка по голове и улыбнулся.
Definitions
To gently touch or stroke someone on the head, often as a gesture of affection, approval, or condescension.
Words
head

noun
голова
pat

verb
похлопывать