This is the 84th most frequent Chinese word.
已经
Already.
In this sentence, "已经" is used to indicate that the action (finishing the homework) has been completed prior to the speaking time, emphasizing the current state.
我已经完成了今天的作业。
I have already finished today's homework.
Here, "已经" qualifies the action of visiting many times as having occurred by the time of speaking, pointing to repeated past actions leading to the present.
她已经去过那家餐馆很多次了。
She has already been to that restaurant many times.
In this example, "已经" is used to illustrate the commencement of a change (the weather turning cold) that has occurred as of the moment of observation.