改错what you shoule do first is to find out what makes...这里的to 到底要不要去掉？什么时候不要

to find out what makes 是不定式作表语！

what you should do first 是主语从句作主语

如果非要改错的话，注意should的拼写，不是shoule

不去掉，be to结构，去掉的话后面跟动名词形式

不用去掉
to find out... 作为宾语，表示动作，去掉to的话就要用finding，而且意思不太合适

要的，这里是不定式做表语。to是需要的。

省略情况如下：
1.动词不定式作感官动词feel \see \notice \watch \find \hear \listen to \observe和使役动词have \make \let等的宾语补足语时,动词不定式符号to省略.如果这些动词用于被动语态,其后的动词不定式符号to不能省略(但let除外).例如:
(1)We often hear him sing the song at home .
(=He is often heard to sing the song at home.)
(2)The y knew her very well.They had seen her grow up from childhood.
(=They knew her very well.She was seen to grow up from childhood.)
注意:
get作"使,让,叫某人做某事"时,要用get sb. to do s t h.结构.例如:
Mother got Tom to buy a pack of sugar.
2.两个或两个以上的动词不定式由连词and \or \than \but连接时,从第二个不定式起,往往省略不定式符号to.但如果强调对比之意时不省略.例如:
(1)She 'd like to take off her coat and have a break.
(2)Th