"Always" is an adverb. It does not affect the form of the verb.
The form of the verb depends on the subject, which is a noun, pronoun, nominal phrase, or nominal clause.
Examples:
He always reads quietly.
They always read quietly.
The boy always reads quietly.
The boys always read quietly.
The boy and the girl always read quietly.
The boy or the girl always reads quietly.
The boy or the girls always read quietly.
The girls or the boy always reads quietly.
The boy, or the girls, always reads quietly.
The girls, or the boy, always read quietly.
That the girls and the boys sometimes read quietly always seems strange.