i feel it hard to keep up with my classmates的句子结构 it后不应该有is吗

i feel(主谓） it （形式宾语）hard （宾补）to keep up with my classmates（不定式作真正宾语）
i feel (主谓）it 【is】hard to keep up with my classmates（宾语从句）
以上两句都对,意思一样.