He can swim but he can't skate.

他会游泳但不会滑冰。

He can swim, but he can not skate.

他能游泳，但他不能滑冰。

He can swim up and down the river many times.

他能够在河里游上游下好多次。

I hear he can swim freestyle, side stroke and breaststroke very well.

我听说他自由泳 、 侧泳和蛙泳都游得非常好.