I have been wondering for some time how does Google translate(or maybe a hypothetical translator) detect language from the string entered in the "from" field. I have been thinking about this and only thing I can think of is looking for words that are unique to a language in the input string. The other way could be to check sentence formation or other semantics in addition to keywords. But this seems to be a very difficult task considering different languages and their semantics. I did some research to find that there are ways that use n-gram sequences and use some statistical models to detect language. Would appreciate a high level answer too.
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