Why "somebody stop me" instead of "somebody stops me" which is grammatically correct?

Question

The famous line of Jim Carrey in the move The Mask: "Somebody stop me!"

Grammatically, I believe it should be "somebody stops me" because somebody is third person singular.

So, why is it acceptable to say "somebody stop me"?

Answer 1

The "stop" in "stop me" is an imperative. It could also be interpreted as an elided form of "[I dare] somebody [to] stop me!"

The imperative has two forms, both of which use the infinitive:

• First person (only plural): Let's stop me!
• Second person: [You] stop me!

We can demonstrate this is the infinitive form by using the verb "to be":

• First person (only plural): Let's be good!
• Second person: [You] be good!

So for the desired meaning it can never be "Somebody stops me!" because it's either an imperative or not the main verb, therefore using the infinitive in either case.

"Somebody stops me" is simple present or habitual:

I try to go to the shops but somebody stops me. (simple present)

Every time I try to go to the shops somebody stops me. (habitual)

Answer 2

Grammatically, I believe it should be "somebody stops me" because somebody is third person singular.

I think 'somebody' is not a 3rd person subject but a 2nd person subject since the sentence is directed to the listener.

Moreover, it's more like an imperative sentence than a declarative sentence, so the basic form 'stop' is correct.