What do you say when someone asks you to say something in another language?

You did say you're learning. Perhaps you don't yet have the confidence, but it'll get better in time. If someone asks me I'll just tell them unless I'm uncertain or don't know it. It depends on who is asking and what. Often times, young people especially want to know curse words.

Well, I just tell them what I know. I don't wanna brag and give them an idea that i am even fluent in that language. I only know very little Japanese. And when I say, very little, it means really verrry little.

Usually that king kind of situation often happens to me, since my family is mix marriage. but i was trained since small for one mother language. When i speak to other family members, i always keep quite a little while and thinking what to say or straight away use English to reply them which is much more easier for me.