An interjection is a short word or expression that communicates an emotion, a reaction, or a call. In Spanish they tend to appear isolated or separated by punctuation marks. They do not form part of the grammatical sentence, although they may accompany it. They tend to change little and are interpreted by context.

Interjections express emotions such as surprise, joy, fear, or pain directly. In writing they are usually marked with exclamation marks. The same sound can change meaning depending on intonation and the situation. Context determines which emotion is being communicated.

Many interjections function as an immediate reaction to something that occurs. They are used alone or at the start of an intervention. They may be followed by a comma if the sentence is extended. They do not require a subject or a verb to have meaning.

Some interjections are used to call attention, warn, or request silence. They often appear in direct interaction situations. They are often accompanied by gestures or voice changes. In writing, they retain their meaning if the context is clear.

Spanish uses interjections specifically for surprise, disbelief, or amazement. Sometimes they are combined with facial or bodily expressions. In writing, exclamation marks mark the intention. They can express from mild puzzlement to strong impact depending on intonation.

For joy, satisfaction or congratulations, interjections are used that reinforce the positive tone. They can appear at celebrations or in enthusiastic responses. They are often combined with gestures like clapping or smiling. The context indicates whether it is approval, relief or jubilation.

Anger or disapproval can be communicated with brief interjections and a firm tone. In conversation they are usually accompanied by facial expression. Some have a protest nuance and others impatience. Proper use avoids misunderstandings in formal situations.

For doubt, fear, or hesitation, interjections are used that signal uncertainty. They tend to appear in situations of insecurity or worry. Sometimes they are drawn out in speech to show hesitation. In writing they can be combined with ellipses to indicate doubt.

Relief and fatigue are expressed with interjections that release tension. They tend to appear after a stressful situation or effort. In speech they can be accompanied by a sigh. In writing, context completes the meaning.

In Spanish, interjections are usually written with opening and closing exclamation marks. If they are combined with a phrase, the comma separates the interjection from the rest. Sound names are written in lowercase if they do not start a sentence. Repetition is written with each element separated by a comma or by a hyphen, depending on the case.

Some interjections vary in frequency or nuance depending on region and register. In formal register, very colloquial or expressive interjections are avoided. In informal register they are common in conversation and messages. The same speaker can alternate interjections depending on whom they are speaking with.