A phoneme is not a letter, and not quite “a sound” you can record with a microphone. It is the smallest piece of speech that can turn one word into another in a language.

A phoneme is not a letterPhoneme不是字母，and not quite 'a sound' you can record with a microphone也不完全是你用麥克風就能錄下來的「一個聲音」。It is the smallest piece of speech它是語言裡最小的一個語音單位 that can turn one word into another in a language能把一個字變成另一個字。

In English, the first sound of big and the first sound of pig are different phonemes: swap them and you get a different word.

In English, the first sound of big and the first sound of pig are different phonemes在英文裡，big開頭的音和pig開頭的音是不同的phonemes：swap them and you get a different word把它們互換，就會變成不同的字。

The actual spoken sound can change a little — the p in pin has a puff of air; the p in spin does not — but English still treats them as the same phoneme. Another language might split them.

The actual spoken sound can change a little實際發出來的音其實會有一點不同——the p in pin has a puff of airpin裡的p帶有一股氣流；the p in spin does notspin裡的p沒有——but English still treats them as the same phoneme但英文還是把它們當成同一個phoneme。Another language might split them換成另一種語言，可能就會把它們分開。

This is classroom and linguistics language; you will not hear it in the market. Teachers use it when they explain why spelling and sound do not always match.

This is classroom and linguistics language這是課堂和語言學裡的用語；you will not hear it in the market你不會在市場裡聽到它。Teachers use it老師會用這個字，when they explain why spelling and sound do not always match來解釋為什麼拼字和發音不一定對得起來。