First grade is an excellent time to start learning about the four main parts of speech in the English language. These four parts of speech are nouns, verbs, adjectives, and prepositions.

Nouns are words that represent people, places, things, or ideas. Examples of nouns include "girl," "dog," "car," and "love."

Verbs are words that describe an action or state of being. Examples of verbs include "run," "jump," "eat," and "be."

Adjectives are words that describe or modify nouns. Examples of adjectives include "happy," "blue," "tall," and "delicious."

Prepositions are words that show the relationship between a noun or pronoun and another word in the sentence. Examples of prepositions include "in," "on," "under," and "with."

By understanding these four parts of speech, you can better understand how to use language to communicate effectively. Keep learning and practicing, and you'll be a grammar expert in no time!