the lingua franca
to be accurate
proficient
to have a natural flair for languages
to master a language
to get by in a language
to immerse yourself in (English)
to have (an) extensive vocabulary
to pick up /acquire a language
skilled at; highly knowledgeable of
to be precise, without too many grammar mistakes
to completely surround yourself with
to know and use a large number of words
learn a language by practising it, rather than by learning it in a class
have natural ability to speak languages well
To learn a language to a native or near-native level.to speak and understand a language very well
a language that is adopted as a common language between speakers whose native languages are different.
know just enough of a language for simple communication