Interjections are words used in speech to express emotion, attitude, or reaction; they can usually stand alone as a sentence or be used with a sentence. They do not denote actions, nor do they function as sentence components, so they typically do not have a subject before or after. Interjections often appear at the start, end, or as insertions in dialogue. In Chinese, interjections are short in form; the specific emotion is determined by tone and intonation.

Oh is used to express understanding, to give a reminder, a mild exclamation, or gentle acknowledgment. When the tone is even, it often means “got it” or “I see.” Lengthening the vowel can intensify emotional color, such as surprise or dissatisfaction. In everyday conversation, “oh” is commonly used as a response to keep the conversation natural. Unlike “ah,” the emphasis of “oh” is on receiving information or prompting.

Wow is used to express strong surprise, admiration, or interest, with vivid emotional color. It often appears standalone or can accompany a full sentence, highlighting the speaker's immediate reaction. It is less common in formal writing and is more often found in spoken language and informal writing. Compared with ya, wow is usually more intense and direct. When using wow, the intonation rises to sound more natural.

Ah is used for exclamation, calling, questioning, or intensifying tone; its meaning changes with intonation and context. Rising intonation often carries a question or mild exclamation, while falling intonation often conveys affirmation or emotional release. In spoken language, ah can soften the tone, making sentences feel more natural and friendly. In exclamatory sentences, ah is often placed at the end or in the middle to strengthen emotional expression. Ah is also commonly combined with other words to form fixed expressions.

Ya is often used to express light surprise, a gentle reminder, or a softened tone; its feel is lighter and more colloquial than Ah. It is common in casual conversations among friends, conveying friendliness and informality. Ending a sentence with ya can make the exclamation sound less stiff. Compared with Wow, ya has lower emotional intensity and is suitable for everyday small surprises. In formal writing, it is rarely used and keeps a spoken flavor.

咦 is used to indicate noticing something unusual, doubt, or surprise, often with a tone of exploration or inquiry. It usually appears when the speaker notices something off or a new situation. In casual speech, it often stands alone or introduces a remark. 咦 is more focused on “where is something wrong” or “how could this be.” When used, pair with facial expressions for stronger effect.

Sigh is used to express sighing, helplessness, disappointment, or mild dissatisfaction; the tone tends downward. It is often placed at the beginning of a sentence to introduce emotion, and can also stand alone as a sentence. In informal speech, prolonging sigh can intensify the sense of helplessness. Unlike Ha or Oh, Sigh typically does not carry positive emotion. The context is usually related to trouble or regret.

Ha is used to express happiness, ease, or teasing; it is often connected to laughter, and can also serve as a response. In spoken language it is common in jokes, easing the atmosphere, or showing friendliness. A standalone Ha can function as laughter sound; with a sentence, it tends to be lighthearted. In group chats or messages, Haha is a common variant indicating more obvious laughter. Unlike Wow, Ha focuses on happiness rather than surprise.

Common Chinese exclamatory sentence structures include “How... Ah,” “Really... Ah,” “So... Ah,” and “Too... Le,” expressing emotion through both structure and intonation. Exclamatory sentences may include interjections or not, relying solely on structure and tone. Adding “Ah” or “Ya” at the end enhances colloquial feel and emotional color. “Too... Le” emphasizes degree, often used for exaggeration or strong feelings. “Good... Ah” is concise and natural, suitable for everyday conversation.

Interjections can stand alone as sentences to express emotion, or can be placed at the beginning or end of an exclamatory sentence to reinforce the effect. Beginning placement often introduces emotion, as in “Wow” or “Sigh,” followed by the specific context. End placement usually pairs with “Ah” or “Ya” to strengthen the overall tone of the sentence. Inserting in the middle should feel natural in speech and not overused. Choosing the right position can make expression more in line with Chinese habits.

The same interjection can express different emotions depending on intonation: a flat tone for statements, a rising tone for surprise or questions, and a falling tone for affirmation or sigh. Chinese exclamatory sentences rely on pronunciation to convey emotional intensity; punctuation alone cannot fully substitute. In speech, lengthening or stressing key words can highlight the emotion. Word choice and tone together create a more natural effect than words alone. Familiarity with local pronunciation helps with being understood and understanding others.