i cant swim
This person has the swimming skills of a brick. They can't float, they can't dog paddle, and they definitely can't keep up in a race. They just stand there, confused.
I can't swim, I tried to swim, the water was like 'what is this?'.
I can't swim, I tried to swim, I looked like a drowning chicken.
I can't swim, I tried to swim, and now I'm just a wet mess.