You can use these functions in your Google spreadsheet to translate text and detect the language in any of the cells. You'll need to type a valid ISO 639-1 language code with either of these functions.
Translate function
Use this function to translate text from and into one of over 40 languages using Google Translate:
=GoogleTranslate("text", "source language","target language")
For example:
=GoogleTranslate("Hola, ¿cómo estás?","es","en") translates into "Hi, how are you?"


Note: You can leave out the target language (in this case, "en") and the function automatically selects the default language of your spreadsheet.
Detect language function
Use this function to find out what languages is being used in a cell:
=DetectLanguage("text")
For example:
=DetectLanguage("Hola, ¿cómo estás?") would give "es" as a result.
