优质解答
I have been studying（或I have studied） English since I was five years old.
I began to study English at the age of 5.
I began to study English when I was five years old.
It was at the age of 5 that I began to study English.
I have been studying（或I have studied） English since I was five years old.
I began to study English at the age of 5.
I began to study English when I was five years old.
It was at the age of 5 that I began to study English.