"I have been here a long time," said Mary.

“我在这里已经很久了。”玛丽说。

"John," he said, looking around him doubtfully, "I think I have been here before."

“约翰，”他疑惑地环顾四周，说道，“我想我以前来过这里。”

I have been here quite a while.

我已经过来好一会儿了。

I have been here the last month.

我在这里已经有一个月了。

I have been here five times.

我到这儿来过五次。