Question

Many foreigners found it a little difficult ________ Chinese.

1. A.
   learn
2. B.
   learning
3. C.
   to learn
4. D.
   learned

Answer 1

C
从句子的结构看，本句中的it是形式宾语，a little difficult是形容词短语作宾语补足语，用来补充说明it，故空格中应填写不定式作真正的宾语。C为正确答案。