I English since I was five years old.A. learnB. learnedC. will learnD. have learned

问题补充：

I English since I was five years old.

A. learn

B. learned

C. will learn

D. have learned

答案：

A. learn

B. learned

C. will learn

(答案→)D. have learned

解析：句中含有since引导的时间状语从句，主句通常用现在完成时，结构为have+过去分词，学习learn的过去分词learned，故本题选D。