Everyone has different skills, and, even though we can be better in maths than in English or the other way around, we all are good, or great, at something! So how can you say "I'm good at something" in Spanish? Of course, you can say "soy bueno en" or "soy buena en", but these are not common expressions that Spanish people would use. Take a look at these colloquial Spanish expressions, which you will hear, for sure, if you ever travel to Spain...
How to Say " I'm good at something " in Spanish
In Spanish, we use the verb dar to say either that we are good or bad at something, or at doing something. But be careful! This expression has a particular structure, very much like the verb gustar (to like). This means that the subject goes at the end of the sentence and it has to be linked to the verb and the pronoun (me, te, le...) need to change, depending on the person (if it's me, you, he or she...). . Also, we need to add an adverb, to say how good (or bad) we are at something: bien, mal, muy bien, fatal, genial... Take a look at this table. You will get a better idea of it.
And, to ask for somebody's abilities, we use the same expression. Take a look at this: