According to time lesson, the verb must agree with the subject in

It could be said that the verb must agree with the subject in number. That is to say, in a sentence the subject - verb agreement should be respected. It would depend on the subject if it is singular or plural.

For example; Sam, together with his siblings, is coming to the party.

In this case, it could be mentioned that the subject is singular, the verb "is" would agree with the subject "Sam".