In modern english there are but few forms indicating person and number in the synthetic forms of the verb. These are:

#1. The third person singular Present Indefinite Indicative

He speaks.

#2. The Future Indefinite tense.

I shall speak – We shall speak

He will speak – They will speak

Verb To Be

The verb to be has suppletive forms for different persons (singular and plural).

Singular Plural
Present Past Present Past
I am am was We are were
He is is was You are were
They are were