How do I teach my first grader the parts of a sentence. She gets the subject confused with predicate. She had a test and she was given a 33F. I want her to succeed in school. She scored 100 in her reading and math. Please help me!

Help her to find the action word in the sentence. That's the verb, also called the simple predicate.

Then ask her who or what is doing the action.

Examples:

Joe ran around the block.

Melissa jumped off the slide.

Most people like apples.

If you post a couple of the sentences she got wrong, we'll be glad to help you explain them to her.