如下：
1：I usually learn English by reading passages.
2：I learn English by working with a group.
3：She learns math by doing a lot of exercises.
4：I study Chinese by taking notes .
5：I study Chinese by listening to tapes .
6：I study Chinese by asking teather for help.
7：We should learn English by using it.
I go to school by taking bus.
He finished his homework by asking his sister for help.
I escaped from washing clothes by taking them back home.
He earned enough money for the travelling by working after school.
1.By doing we learn.
經一事，長一智。
2.By doing nothing we learn to do ill.
閑逸是萬惡之源。
3.I wonder what he is at by doing so.
我不知道他這樣做是什么意思。
4.By doing so you will wash away your sins.
這樣做你會洗去你的罪過。
by doing sth 的意思是“通過做某事”
分析：
1、by 是介詞,用來表示方法、手段、方式,意思是“憑借；靠；用；通過”,后接動詞時要-ing形式。即 by doing sth .
如：
I improve my English by listening to English songs .
我通過聽英語歌提高英語。
He bacame a 買粉絲llege student by working hard.
他通過努力學習成為了一名大學生。
拓展（by常見的其它用法）：
1、by+地點名詞。表方位，意為：“在…旁邊”。
如：
He sits by the window.
他坐在窗邊。
2、by+時間名詞。意為：“到…時（已發生某事），此時謂語多用完成時；最晚、不遲于…，在…之前”。
如：
We had learned two hundred words by the end of last term .
到上學期末為止我們學了兩百個詞。
3、by+交通工具、交通方式名詞（名詞前不加冠詞，不變復數）。意為：“通過…，由…，乘…”。
如：
1). He goes to school by bus every day.
他每天乘公共汽車上學。
2). The man entered the room by the back door.
那人通過后門進入了房間。
4、by+身體部位名詞或衣服名詞。表示被抓住身體/衣物的某一部分，常與動詞catch/seize/take/hold/grab等連用。
如：
The policeman caught the thief by the arm.
警察抓住了小偷的胳膊。