Interjections are words or short phrases that show emotion, reaction, or sudden feeling. They can stand alone or appear at the start or end of a sentence. They do not change form and do not fit into the main grammar of the sentence. Their main purpose is to express the speaker’s attitude quickly.

Some interjections show surprise, some show pain or discomfort, and some manage the flow of conversation. In casual speech, these are frequent and may carry different force depending on tone. Written interjections often rely on punctuation to show strength. The core meaning stays stable across situations.

Word/Phrase	Definition
Oh	This expresses surprise or realization.
Wow	This expresses strong admiration or amazement.
Ouch	This expresses sudden pain or discomfort.
Uh	This signals hesitation or mild doubt.
Hey	This gets attention or calls someone.
Yay	This expresses happiness or relief.

Interjections often use an exclamation mark when the emotion is strong or sudden. A comma can be used when the interjection is milder or part of a longer sentence. In writing, consistent punctuation helps the reader understand the intended force. The interjection itself does not change form with punctuation.

Interjections most commonly appear at the beginning of a sentence. They can also stand alone as a complete utterance. Sometimes they appear at the end of a sentence, especially in conversational writing. They do not take subjects or verbs and do not link clauses.

Interjections express emotions or reactions quickly without joining the main grammar of the sentence. They are chosen for the feeling they convey and are marked in writing by punctuation. Using them effectively depends on placement and clear punctuation, not on changing their form.