改为一般疑问句的方法介绍如下：
要将陈述句变成一般疑问句,可以遵循下列步骤：
1.看句中有没有be动词（am、is、 are、 was、 were）、助动词（do、does、did、 have、 had）或情态动词（can、must、will、may等）,如果有,将其提到句首,句末打上问号即可.
例：It was rainy yesterday.
Was it rainy yesterday?
Tom's father can play the piano.
Can Tom's father play the piano?
I have finished my homework.
Have you finished your homework?
2.如果句中没有be动词、助动词或情态动词,则根据谓语动词的形式借助do的相应形式放在句首.
具体方法是：
①如果谓语动词是原形,则借do；
②如果谓语动词是一般现在时第三人称单数形式,则借does；
③如果谓语动词是过去式,则借did.
需要注意的是,借does或did后,原句的谓语动词要变回原形.
例：They go to school by bike.
Do they go to school by bike?
Bill gets up at 6:30 every day.
Does bill gets up at 6:30 every day?
The students saw a film yesterday.
Did the students see a film yesterday?
二、陈述句变一般疑问句应注意的事项
陈述句变成一般疑问句除了遵循上述规则以外,还应注意下列几点：
1.如果陈述句中有第一人称,则变问句时最好要变为第二人称.
例：I usually have lunch at school.
Do you usually have lunch at school?
My father is playing soccer.
Is your father playing soccer?
2.如果陈述句中有some,则变问句时往往要变成any .
例：There is some water on the playground.
Is there any water on the playground?
3.复合句变一般疑问句通常只变主句,从句不变.
例：I know he comes from Canada.
Do you know he comes from Canada?
4．如果句中含有实义动词have且表示“有”时,除借do外,也可将其直接提到句首.
例：I have some friends in America.
Have you any friends in America?/Do you have any friends in America?
三、总结：将陈述句改成一般疑问句的方法：三步法
1、有be动词,则把be动词放在句首,剩下的照抄,（some 改成any,I改成you,my改成your,）句点改成问号.
2、有情态动词,则把can,shall,will等放到句首,剩下的照抄,（some 改成any,I改成you,my改成your,）句点改成问号.
3、没有be动词,也没有情态动词的,则将助动词Do/Does/Did放到在句首,谓语动词变回原形,剩下的照抄,（some 改成any,I改成you,my改成your,）句点改成问号.