Teacher now tells you that this is the verb “to be”

I am

You are

He is

She is

We are

You are

They are

So what happened to the “be”?

It used to be there didn’t it? Old maps with “Here be dragons”, old English with “Be thou from afar?”

I Googled the question and am now more confused than I was before. Apparently, the modern verb is a combination of two (some say three, because am/was is itself a conglomerate) old verbs. It has been called “an accidental conglomeration from different Old English dialects (Weekley).

So there you are. Just be pleased that you already know English!