I find that it is useful to learn English.it是形式主语,

I find that it is useful to learn English.it是形式主语, 将I find it is useful to learn English well. 将“I find it is useful to learn English well"转换成同义句"I find -- I find it useful to learn English well It is so hard to lear i find it's useful to learn English.为什么可以改成i find it useful I think——（this,that,it）is very useful to learn english well. 几个英语问题句型转换i find it is useful to learn English well.（改为简单句）i 1 I find it useful _____(learn) English well. I find it to learn English. I FIND IT IMPORTANT TO LEARN ENGLISH. It is important to learn English.是主语从句吗? I think it hdrd to learn English.哪个是主语?