Mandarin has four tones; every syllable must carry one tone. The tone determines the meaning of a word, and incorrect tones may lead to misunderstandings. The same pinyin can represent different words under different tones.

The first tone is a high level tone, steady and flat. The second tone is a rising tone, rising from mid to high. The third tone is a falling-rising tone, falling first then rising. The fourth tone is a falling tone, starting high and quickly falling to low.

When marking tones in pinyin, only one tone mark is placed per syllable. When the syllable contains a, o, and e, the tone is preferentially marked on those vowels. If there is no a, o, or e, mark the tone on i or u according to pinyin rules. Correct tone marking helps clear expression and listening comprehension.

In Mandarin, word stress typically falls on the main syllable of a word. For disyllabic words, stress is usually on the first syllable to keep tones clear. Stress highlights information and helps listeners identify keywords. In a set of parallel words, each word keeps its own clear stress.

Mandarin has neutral tones, which shorten and lighten syllables, no longer maintaining the full four tones. Neutral tone often appears at the end of words or in attached components. Neutral tone makes sentences more natural and fluent, but does not change the basic structure of the word. When marking, tone marks are usually not written; use pinyin directly.

Declarative sentences usually have a flat or slightly falling intonation, conveying complete information. Yes-no questions typically rise at the end to invite a response. For choosing questions, the intonation rises at the chosen option, and at the end of the sentence it may be flat or slightly falling. Intonation and tones work together to convey mood and intent.

In a sentence, the most important information is usually emphasized with emphasis. The speaker can shift the emphasis location depending on context, thereby changing the sentence's focus. Information focus is not the same as a change in tone; it is a local elevation of pitch and intensity. Correct focus selection helps clearly convey intent.

Tone is the main clue for distinguishing word meanings; listening comprehension relies on accurate tones. Stress helps identify sentence structure and information focus. Neutral tone and intonation make expressions natural, but cannot replace the tones themselves. In real communication, clear tones and appropriate emphasis together improve comprehensibility.

Rising intonation at the end of questions often conveys friendliness and expectation of a response. Requests and suggestions with a steady tone are usually more polite. Excessive falling may be heard as harsh, especially in requests. The choice of intonation affects the listener's perception and conveys attitude together with content.

In daily speech, syllables flow naturally, but each tone must be preserved. Neutral tones and weak pronunciation often facilitate linking, making sentences smoother. Linking is not merging tones; it is maintaining smooth connections under the tones. In practice, prioritize clear tones first, then pursue natural fluency.