Google Translate uses statistical machine translation last time I checked at least , based on a corpus of text . This means that you need a corpus database with sentences written in two languages , so the system can learn to translate between those two languages . So , for every combination of languages , you need a database with sentences written in both languages , and the translation quality depends heavily on the size of the corpus and quality of the sentences and translations in that corpus . I don ' t know tofrom what language you want to translate fromto English , but the quality of the translation depends heavily on the size of the corpus . I understand what you mean , it is far from perfect for every combination of languages , but I thought you would be intereseted to know . And by the way , if you translate from Mandarin to English or the other way around , you ' re in luck q 4 y 0 KOeXViIfeatureyoutu . bet 8 m 25 s long story short still based on a corpus of text , but the computer uses a neural network to learn from it , instead of simple statistics If , by chance small chance , I know , you ' re intersted in the actual statistics , then read A statistical approach to machine translation from Brown et alii 2002 . It ' s quite interesting if I say so myself .