Mandarin Tone Pairs: The Cheat Sheet That Finally Makes Sense of Tone Sandhi

Mandarin has four tones. Pair them up and you get sixteen tone pairs. Learn the sixteen pairs and you have covered every Mandarin sentence you will ever meet, because every Mandarin sentence is just a string of pairs. This article is the cheat sheet: the full 16-pair table, the four sandhi rules that change what you hear, the ten phrases that hide those rules in plain sight, and a five-minute daily routine for locking them in.

If you have ever wondered why native speakers say “ní hǎo” instead of “nǐ hǎo”, or why “bù duì” comes out as “bú duì”, this is the page that finally makes the pattern click.

Why tone pairs feel impossible (and why they are not)

The mistake most learners make is to memorise tones one syllable at a time. That works in a textbook. It falls apart the first time someone speaks at native speed, because real Mandarin is not a string of standalone syllables. It is a string of pairs.

When two syllables sit next to each other, they interact. The first tone can change. The contour can compress. The rhythm can shift. None of this is random. It follows a small set of rules that Mandarin speakers apply automatically from infancy. Your job as a learner is to know the rules well enough that the same speech is transparent to you.

There are only four base tones, only sixteen pairs, and only three sandhi rules that change a tone. Add a fourth rule for the chameleon numeral “yī” and you have the whole system. That is the good news. The bad news is that the rules only become obvious in context, which is why this page ends with a list of the ten highest-leverage phrases to drill.

The four base tones (a 60-second refresher)

Keep the first tone flat, lift the second tone, give the third tone the dip-and-rise in isolation, and drop the fourth tone sharply. Add a light neutral tone for particles like “ma” and “de” and you have the entire Mandarin tonal palette. Everything in this cheat sheet starts from these four contours.

The full 16-pair tone combinations table

Take the four tones and pair each one with each of the four tones. That gives you sixteen combinations. Most of them are easy. A handful of them trigger sandhi rules that change what you actually hear. The table below is the cheat sheet. Memorise which pairs are stable and which pairs change.

In the “what you hear” column, sandhi changes are shown in italics.

Three quick reads of the table:

• Only one cell changes the lexical tone. T3 + T3 becomes T2 + T3. Every other change is a compression of the third-tone contour, not a change of tone identity.
• “Half-third” is everywhere. Any third tone sitting next to a non-third tone compresses into a low falling shape. The pinyin still shows the caron, but the contour is shorter.
• Two T4s in a row is the easy one to forget. In slow, careful speech it stays two T4s. In fast connected speech the first T4 can soften, but it does not formally change to T1 the way T3 changes to T2. Treat it as stable unless you hear otherwise.

The four sandhi rules you cannot skip

The table above mentions “half-third” and “third-tone sandhi” without explaining them. These are the four rules that produce every change.

Rule 1: Third-tone sandhi (T3 + T3 becomes T2 + T3)

When two third tones meet, the first becomes a second tone. The second stays third.

• nǐ hǎo 你好 (hello) is pronounced ní hǎo.
• lǎo shǔ 老鼠 (mouse) is pronounced láo shǔ.
• hěn hǎo 很好 (very good) is pronounced hén hǎo.

When three third tones meet in a row, the rule cascades: usually T2 + T3 + T3, with sandhi applied to the first syllable. The textbook example is zhǎn lǎn guǎn 展览馆 (exhibition hall), pronounced zhán lǎn guǎn. The two-and-two pattern is also common, especially in longer compounds. Train your ear to recognise “T3 changes when stacked” and the specifics sort themselves out.

Rule 2: The half-third (T3 before a non-T3 compresses)

A third tone sitting next to any non-third tone is rarely given the full dip-and-rise. Instead it compresses into a low falling contour. The pinyin keeps the caron so you know what to write, but the sound is shorter.

• hěn hǎo 很好 (very good): the “hěn” sounds shorter than the textbook shape.
• wǒ de 我的 (my): the “wǒ” drops and stops rather than rising.
• mǎi le 买了 (bought): the “mǎi” is a low fall.

The half-third is why native speech sounds “flatter” than the textbook. Learners who insist on the full dip in every position sound robotic. Learners who compress it correctly sound natural.

Rule 3: The bù (不) tone change

The negation “bù” (fourth tone) changes to “bú” (second tone) only when it sits directly before another fourth tone. In every other position it stays fourth.

• bú duì 不对 (incorrect): “bù” → “bú”.
• bú shì 不是 (is not): “bù” → “bú”.
• bù hǎo 不好 (not good): stays “bù hǎo” because “hǎo” is third tone.
• bù lái 不来 (does not come): stays “bù lái” because “lái” is second tone.
• bù xíng 不行 (won’t do): stays “bù xíng” because “xíng” is second tone.

The rule is small but high-frequency. Over-applying it (“bú hǎo”, “bú lái”) is one of the most common English-speaker tells.

Rule 4: The yī (一) tone change

The numeral “yī” is a chameleon. It keeps its first tone only when it stands alone, when used as an ordinal, or at the end of a phrase. Everywhere else, it changes.

Examples:

• yí gè 一个 (one / a): “yī” → “yí” before the fourth-tone “gè”.
• yì tiān 一天 (one day): “yī” → “yì” before the first-tone “tiān”.
• yì bǎi 一百 (one hundred): “yī” → “yì”.
• dì yī 第一 (first, ordinal): “yī” stays first tone.

The mnemonic is the opposite of “bù”: “bù” changes only before T4; “yī” changes everywhere except when alone, ordinal, or final. Drill both rules until the contrast is automatic.

Common phrases that hide tone sandhi in plain sight

The ten phrases below cover every rule in this cheat sheet. If you can produce these ten fluently, you can produce roughly 80 percent of the sandhi patterns you will meet in real conversation.

1. ní hǎo 你好 (hello) - third-tone sandhi.
2. hén hǎo 很好 (very good) - third-tone sandhi across a word boundary.
3. láo shǔ 老鼠 (mouse) - third-tone sandhi inside a compound.
4. bú duì 不对 (incorrect) - the “bù” change.
5. bú shì 不是 (is not) - the “bù” change with “shì”.
6. yí gè 一个 (one / a) - the “yī” change before T4.
7. yì tiān 一天 (one day) - the “yī” change before T1.
8. yì bǎi 一百 (one hundred) - the “yī” change before a third tone.
9. kě yǐ 可以 (may / can) - half-third on “kě” before T3.
10. mǎi le 买了 (bought) - half-third on “mǎi” before the neutral tone.

Pick five of these and drill them out loud for a minute each. After a week, the sandhi patterns are muscle memory.

A five-minute daily practice routine

The drill below is the shortest routine that actually moves the needle. It assumes you have ten minutes and want steady improvement without burning out.

Five minutes a day is enough if you do it daily. The single biggest predictor of tone accuracy is consistency, not session length. Two minutes every evening beats thirty minutes on Sunday.

Common English-speaker errors

The five errors below cover the majority of the mistakes you will hear from learners - and the mistakes you will catch yourself making.

Error 1: Saying nǐ hǎo as two third tones

The single most common Mandarin mistake in the world. “Nǐ hǎo” with two third tones sounds careful and robotic. Native Mandarin is “ní hǎo”, with second and third.

Fix: rehearse the phrase ten times a day for two weeks. Pair it with a gesture if you have to - the muscle memory will lock in.

Error 2: Forgetting sandhi across word boundaries

Third-tone sandhi applies across word boundaries, not just inside words. Learners who know “lǎo shǔ” gets the sandhi often forget “hěn hǎo” because it is two words, not one. Same rule, different unit.

Fix: treat every T3 + T3 sequence the same way regardless of where the boundary sits. If two third tones meet, the first becomes second.

Error 3: Over-applying the bù change

English speakers who have just learned the “bù → bú” rule often apply it everywhere. “Bú hǎo”, “bú lái”, “bú xíng” - all wrong. The “bù” change fires only before another fourth tone.

Fix: before saying a “bù” phrase, check the next tone. If it is fourth, raise. If it is anything else, stay low.

Error 4: Pronouncing 一 (yī) as first tone in compounds

Once “yī” is sitting next to another syllable, it almost always changes. Saying “yī gè” instead of “yí gè” or “yī tiān” instead of “yì tiān” sounds stilted and slow.

Fix: rehearse “yí gè” and “yì tiān” as set phrases. The shapes stick faster as chunks than as rules.

Error 5: Treating half-third as wrong

Learners who have memorised the textbook dip-and-rise sometimes panic when they hear native speech and the dip is missing. The dip is the isolated form. In connected speech the third tone compresses. Both are correct.

Fix: accept that half-third is the connected-speech default. Drill isolated “mǎ” with the full dip for production; accept the half-third when listening.

FAQ

Do I really need to learn all 16 pairs?

Yes, but most of them are stable. You only need the four sandhi rules to understand the cells that change. Memorise the table once, then drill the rules until the changes become reflex.

What about tone pairs that span more than two syllables?

The same rules apply, cascading. Three third tones usually resolve as T2 + T3 + T3. Four third tones resolve as T2 + T3 + T2 + T3 or similar, depending on the word boundaries. The general principle: every T3 + T3 boundary triggers the change.

Is T4 + T4 really stable? I think I hear a change sometimes.

In slow careful speech, T4 + T4 is two sharp drops. In fast connected speech the first T4 can soften or shorten, but it does not formally change to T1 the way third-tone sandhi changes tone identity. Treat T4 + T4 as stable for production purposes and let your ear absorb the variation.

Are neutral tone and the half-third the same thing?

No. The neutral tone is a fifth tone category, used on grammatical particles and a handful of second-position syllables like “ma” and “de”. The half-third is a compressed third tone, not a separate category. They sound similar because both are short and unstressed, but the rules that produce them are different.

How long until tone pairs feel natural?

Most learners reach functional accuracy on the sandhi rules within four to six weeks of daily drilling. Production mastery - sounding natural in conversation - takes another three to six months. The good news is that sandhi is rule-based, not memorisation-based, so once the rules click the rest is just ear training.

Hear real tone pairs in ReadDeck

Reading the rules is necessary. It is not enough. The muscle you are training is your ear, and ears learn by listening. The fastest path is daily exposure to native audio with transcripts, followed by focused sandhi drills and minimal-pair work.

ReadDeck is the offline Mandarin reader we built for exactly this loop. Every lesson ships with audio, every word is tappable for isolated pronunciation, and the FSRS review system schedules tone drills at the moment your ear is about to forget them. The app is free, offline, and Mandarin-only.

If you want a parallel audio course to pair with reading, Audio Deck ships transcripts alongside every audio lesson, which makes the sandhi rules above much easier to hear in context.

When you are ready for the full picture, the Mandarin tones hub links to the free four-tone drill packs and the audio-first training method. Your ear is the muscle. Train it every day and the tone pairs will click within a month. To see how your sandhi and tone-pair accuracy holds up under exam conditions, HSK Quiz runs free adaptive listening mocks scored against the official HSK pass mark.