Are you good at languages?
Are you quite at home with any foreign language?
I’m quite at home with my English.
I know three languages fairly well.
I have a good command of the language.
I have a working knowledge of English.
They take me for an Englishman.
You speak English clearly (fluently, fairly well, abominably).
Your English has improved.
I am learning (mastering) a language.
I am enriching the language with new vocabulary.
Your vocabulary is enormous.
He is very good at (talented for, gifted for) languages.
He is very quick at picking up languages.
My English needs brushing up.
My English is degrading.
My knowledge of the language is very small.
He has a smattering of German.
He speaks in ruinous (broken) English.
He speaks poor English. (His English is poor).
You speak with a very strong accent.
He butchers (murders) a language.
I'm going to have a dig at English. (I want to take up English).
I took up English last year, but I dropped it again.
I’ll have to learn it all over again.
Doesn't your ear tell you whether the sentence is right or wrong?
Latin is a dead language.
These two languages are similar.
Don't use strong language.
I won't have any language here.
Isn't it too slangy?
What is the English for...?
He sprinkled his speech with such words as...
Where did you pick up that word?
I can explain it to you in plain English.
Your language is quite flexible.
My English is truly limited.
I know grammar by ear only, not by note, not by the rules.
The majesty and grandeur of the English language.
Language is the greatest possession we have.
My spelling is wobbly. It is good spelling, but it wobbles and the letters get in the wrong places.