So, can you?
Native English speaker here, can understand Mandarin for the most part but my speech and writing are awful. Learning glorious Nippon weeaboo language now. A lot of slang over here has roots in Malay or Chinese dialects, so I know a few words from those. Considering trying German or French for the next university semester.
I've always been really impressed by people who don't have English as their native language and master it anyway. Being fluent in more than one language sounds awesome.