Interjections are short words or expressions that express emotions, reactions, or feelings directly. They can form a sentence by themselves or appear between sentences to mark the speaker's intention. They do not change form and do not themselves carry a subject or verb tense. They function as a shortcut to show what we feel or think at the moment.

The main function of the interjection is to indicate the speaker's emotional state or to draw attention to a reaction. It can express surprise, joy, pain, fear, doubt, irritation, among other feelings. Often, it also organizes the conversation, opening or closing turns of speaking. In dialogues, it helps make speech more natural and expressive.

Interjections are normally followed by an exclamation point to mark intensity. They can also be accompanied by a comma when they appear in the middle or at the beginning of a sentence, with a less explosive tone. In texts, punctuation helps differentiate a quick reaction from a more neutral comment. The choice of punctuation changes the expressive strength without changing the word.

Interjections of surprise show that something was unexpected for the speaker. They can indicate positive or neutral surprise, depending on the context and intonation. In Brazilian Portuguese, some forms are very common in everyday speech. The same interjection can vary in meaning with the tone of voice.

Interjections of joy indicate contentment, satisfaction, or relief. They are used to celebrate a result, receive good news, or show pleasure. They can appear on their own as a reaction or accompanied by an explanation. In speech, they typically come with rising intonation and a quick tempo.

Interjections of pain and startle communicate physical discomfort or an abrupt reaction to an event. They are used automatically in situations of impact or discomfort. They can be repeated to increase expressiveness in speech. In dialogues, they signal that the speaker needs attention or care.

Interjections of irritation show discontent, impatience, or disapproval. They can mark a boundary in the conversation or react to something considered inappropriate. The context defines whether the tone is light, playful, or truly serious. In texts, they often come with an exclamation to reinforce the intention.

Interjections of doubt indicate hesitation or distrust of the speaker regarding something. They typically appear when something is not clear or seems strange. They can introduce a question or a critical comment. In speech, they are accompanied by a pause and a questioning look.

Interjections of calling are used to attract someone's attention or to start an interaction. They typically open turns of speech or interrupt an action to request attention. They can be used with courtesy or urgency, depending on the context. In writing, they appear very often in dialogues.

Some interjections are more common in specific regions of Brazil and of Portugal. Regional use can bring local identity and mark belonging in a conversation. The same situation can receive different interjections depending on the region. Knowing these variations helps understanding in different contexts.