Indo-European is the name of a very large family of languages, and also the name of the ancient language they all grew out of. English belongs to it. So do German, Dutch, and the Nordic languages; French, Spanish, Italian, Portuguese, and Romanian; Russian, Polish, and Czech; Greek; Persian; and Hindi, Bengali, Urdu, and many other languages of northern India. Chinese does not belong to it, and neither do Japanese, Korean, Arabic, Hungarian, Finnish, or Turkish.

Indo-EuropeanIndo-European（印歐語系） is the name of a very large family of languages是一個非常龐大的語言家族的名稱 and also the name of the ancient language they all grew out of同時也是這些語言共同源出的那個古語言的名稱 English belongs to it英語屬於這個語系 So do German, Dutch, and the Nordic languages德語、荷蘭語，和北歐語言也是 French, Spanish, Italian, Portuguese, and Romanian法語、西班牙語、義大利語、葡萄牙語，和羅馬尼亞語 Russian, Polish, and Czech俄語、波蘭語，和捷克語 Greek希臘語 Persian波斯語 and Hindi, Bengali, Urdu, and many other languages of northern India還有印度北部的印地語、孟加拉語、烏爾都語，和許多其他語言 Chinese does not belong to it中文不屬於這個語系 and neither do Japanese, Korean, Arabic, Hungarian, Finnish, or Turkish日文、韓文、阿拉伯文、匈牙利文、芬蘭文，和土耳其文也都不屬於

The idea is this: several thousand years ago, one group of people spoke one language. As they moved apart, their speech slowly drifted, and after enough centuries the branches could no longer understand each other — the way Latin quietly turned into French, Spanish, and Italian, but over a much longer time.

The idea is this概念是這樣的 several thousand years ago好幾千年前 one group of people spoke one language有一群人說著同一種語言 As they moved apart隨著他們逐漸分散開來 their speech slowly drifted他們的語言也慢慢產生變化 and after enough centuries經過夠久的世紀之後 the branches could no longer understand each other這些分支彼此就再也聽不懂對方 the way Latin quietly turned into French, Spanish, and Italian就像拉丁文悄悄演變成法語、西班牙語，和義大利語一樣 but over a much longer time只是花的時間長得多

Nobody wrote that first language down; scholars worked backwards from the modern languages to reconstruct it, and its words are written with a * to mark 'this is our best reconstruction, not something anyone found'. This is why English mother, German Mutter, Latin mater, and Sanskrit matar look so alike — they are not borrowings, they are cousins.

Nobody wrote that first language down沒有人把那個最初的語言寫下來 scholars worked backwards from the modern languages學者是從現代語言反推回去 to reconstruct it重建出這個語言 and its words are written with a *而它的字都會標上一個* to mark 'this is our best reconstruction, not something anyone found'用來標明「這是我們最好的重建結果，不是真的找到的東西」 This is why這就是為什麼 English mother, German Mutter, Latin mater, and Sanskrit matar英語的mother、德語的Mutter、拉丁文的mater，和梵文的matar look so alike看起來這麼像 they are not borrowings它們不是互相借用的 they are cousins而是同源的表親關係

The word is used as an adjective ('the Indo-European languages') and as a name for the family or the parent language ('this word goes back to Indo-European'). You may also see PIE, short for Proto-Indo-European, which means specifically the reconstructed parent language rather than the whole family. Write it with a capital I, a capital E, and the hyphen.

The word is used as an adjective這個字可以當形容詞用 ('the Indo-European languages')（像「the Indo-European languages」） and as a name for the family or the parent language也可以當語系或母語言的名稱 ('this word goes back to Indo-European')（像「this word goes back to Indo-European」） You may also see PIE你也可能會看到PIE short for Proto-Indo-European是Proto-Indo-European的縮寫 which means specifically the reconstructed parent language專門指那個被重建出來的母語言 rather than the whole family而不是指整個語系 Write it with a capital I, a capital E, and the hyphen寫的時候I和E都要大寫，中間要加連字號