[译] 他已学会游泳了。
[误] He has learned swimming.

[正] He has learned to swim.
[注] learn doing sth. 表示“学习做某事”，通常侧重于学习的过程；而 learn to do sth. 表示“学会做某事”，强调学习的结果。所以语句的意思只含有他已开始学游泳，但并没有说明是否已学会。