A tonne is a unit of weight equal to 1,000 kilograms — the same thing Taiwanese students call 一公噸. It is the metric unit, used almost everywhere in the world for heavy things: cargo on a ship, rice harvests, rubbish collected in a year, the weight of a whale, carbon dioxide put into the air.

A tonne公噸 is a unit of weight equal to 1,000 kilograms是等於一千公斤的重量單位 — the same thing Taiwanese students call 一公噸就是台灣學生說的一公噸。It它 is the metric unit是公制單位，used almost everywhere in the world for heavy things全世界幾乎都用它來講重的東西：cargo on a ship船上的貨物、rice harvests稻米收成、rubbish collected in a year一年收集的垃圾、the weight of a whale鯨魚的重量、carbon dioxide put into the air排放到空氣中的二氧化碳。

Here is the part worth being careful about. English also has a word 'ton', spelled without the -ne, and it is a different amount. In Britain a ton is about 1,016 kg; in the United States a 'ton' is about 907 kg. So the three words sit close together but do not match.

Here這裡 is the part worth being careful about是需要小心的地方。English英文 also has a word 'ton'還有一個字 ton，spelled without the -ne拼法沒有 -ne，and it而它 is a different amount是不一樣的重量。In Britain在英國，a ton一噸 is about 1,016 kg大約是1,016公斤；in the United States在美國，a 'ton'一噸 is about 907 kg大約是907公斤。So所以 the three words這三個字 sit close together but do not match雖然很接近但對不上。

To avoid this mess, scientists and international writing often say 'metric ton' or write the symbol 't'. American writing mostly does not use the spelling 'tonne' at all, so if you are reading an American article, 'ton' there probably means the American 907 kg one.

To avoid this mess為了避免這種混亂，scientists and international writing科學界和國際性的文章 often say 'metric ton' or write the symbol 't'.常常會說 'metric ton'（公噸）或直接寫符號 't'。American writing美式寫法 mostly does not use the spelling 'tonne' at all大多完全不用 tonne 這個拼法，so if you are reading an American article所以如果你在讀美國的文章，'ton' there那裡的 ton probably means the American 907 kg one很可能指的是美制那個907公斤的噸。

In casual speech there is also a loose use meaning simply 'a huge amount', but people almost always spell that one 'ton' or 'tons': 'I've got tons of homework.' You would not write 'tonnes of homework' — the -ne spelling stays with real measuring.

In casual speech在口語裡，there is also a loose use還有一種鬆散的用法 meaning simply 'a huge amount'單純指「一大堆」，but people大家 almost always spell that one 'ton' or 'tons'幾乎都拼成 ton 或 tons：'I've got tons of homework.'像是「我有一大堆功課」。You你 would not write 'tonnes of homework'不會寫成 'tonnes of homework' — the -ne spelling stays with real measuring因為 -ne 的拼法是留給真正在測量重量的時候用的。