Idon't know what to do 中的"what to do "是句子吗?what 是连词，而to do 是做什么成分？

I don’t know ,what idon’t understand . Idon't know what to say…I'm just thinking of you a lot at this moment. ：idon't know what to say …i'm iust thinking of you a lot at this moment Idon't know what was the matter还是I don't know what the matter was Idon't know what to do 中的what to do 是句子吗?what 是连词，而to do 是做什么成分？ Sorry,Idon't know意思 I love her very much but Idon't know how to express mylove to her. -Do you know what Mr Franklin is -Idon't really know exactly about it.But Ithink he can be____buta lawyer. I don't know how to pronounce the word.（同义句） Idon't know the _____ _____ the word. I don't konw what you I don't konw what you know Ｙou Ｋnow ＩＤon't Ｋonw 这两句给我解释哈也 don't know what to Idon't know what he (ture) feltIdon't know what he (ture) felt 用所给单词的适当形式填空 I can't help ___ the job.because Idon't know how to do it.+麻烦告诉我原因 ----（　　）?－－－Sorry,IDON'T　KNOW a　Whose　shirt　is　it　　b----（　　）?－－－Sorry,Idon＇t　know．a　Whose　shirt　is　it　　b　　Which　shirt　is　it　　c　　what　shirt　is　it I don`t know how i was drawn to you!Idon`t know when I staned to love you!中文是啥意思 How do I live without your love?Idon't know Idon't know the boy b___jim,who is he Idon't know which hat was his 和 Idon't know which hat his was哪个对?