Invite Jim on our fishing trip.

In the above sentence can you tell me what words modify the predicate. I think
the predicate is invite but I'm not sure.
if so would on our fishing trip be the
predicate modifiers. And also would Jim be the subject of the sentence?

You're right -- "invite" is the main verb. This is a command type of sentence (as opposed to a statement, a question, or an exclamation). Therefore, the subject is understood, not stated.

If the subject is not stated, then all the rest of the sentence is the complete predicate. "Jim" is the direct object.

http://english.unitecnology.ac.nz/resources/resources/exp_lang/sentence.html

Scroll down far enough to read about command (imperative) sentences.

Yes, "invite" is the simple predicate (the verb).

The whole sentence is the predicate. "Jim" is the direct object of "invite," and "on our fishing trip" is a adverbial prepositional phrase modifying "invite."

The subject is the understood (You).

wow didn't know that one, thanks!

In the sentence "Invite Jim on our fishing trip," the main verb is "invite."

To determine which words modify the predicate, we need to identify the direct object of the verb "invite." A direct object is the person or thing that receives the action of the verb. In this case, the direct object of the verb "invite" is "Jim." So, "Jim" is not a modifier of the predicate but rather the direct object of the sentence.

As for the phrase "on our fishing trip," it is a prepositional phrase that acts as an adverbial modifier. It provides additional information about where the action of the verb is taking place. Specifically, the phrase tells us that the invitation is for Jim to join the fishing trip. Therefore, "on our fishing trip" is a modifier of the predicate "invite."

In terms of sentence structure, Jim is the indirect object of the verb "invite." The subject of the sentence is missing in the provided sentence. For a complete sentence, there should be a subject performing the action.