My native language is Polish. I speak English, Russian and Ukrainian, although haven't used the latter two for years, so I'm rusty when speaking. I still understand and read them fluently. I also speak and read some Chinese (Cantonese). Ukrainian and Cantonese are languages I learnt as an adult, not a kid. I started learning Russian when I was 12, but really learnt it when I was in early twenties (I studied it). English - when I was 14.
I was also learning French, German, Czech and Latin, but can't say I know those languages.