自学的英文是self-taught。
例句：
1、保罗是自学的，他四年前才开始对摄影产生兴趣。
Paul is self-taught and became interested in photography just four years ago.
2、富兰克林在很大程度上是自学成才的。他可能是一个天才，但是在体现美国人的动手能力和创造性方面，他并不是一个例外。
Franklin, who was largely self-taught, may have been a genius, but he wasn't really an exception when it comes to American making and creativity.
3、我自学了弹钢琴。
I taught myself how to play the piano .
4、你可以自学。
You can study by yourself.
5、这些课程他是自学的。
He studied these subjects on his own.