* 똑똑해요 (ttok-ttok-hae-yo): This is a common and versatile way to say "I'm smart." It implies general intelligence and quick-wittedness. It's polite and suitable for most situations.
* 똑똑하다 (ttok-ttok-ha-da): This is the declarative form of 똑똑해요. It's less polite and generally used in informal settings or when speaking to close friends and family.
* 영리해요 (yeong-ri-hae-yo): This translates to "I'm clever" or "I'm intelligent." It suggests a more cunning or resourceful type of smartness. It's also polite.
* 머리가 좋아요 (meo-ri-ga jo-a-yo): This literally means "My head is good," implying intelligence. It's a more straightforward and slightly less common way to say "I'm smart," but still polite.
Which one you choose depends on the situation and who you're talking to. For most situations, 똑똑해요 (ttok-ttok-hae-yo) is a safe and accurate choice.