给定一个英语作文，进行语法检查和修改，并提供修改后的版本。
Yesterday, me and my friends go to the park to play. We have a lots of fun there. I play the swing and we have a picnic. And we see alot of birds.
Yesterday, my friends and I went to the park to play. We had a lot of fun there. I played on the swing, and we had a picnic. We saw a lot of birds. 

Revised Version:
Yesterday, my friends and I went to the park to play, and we had a lot of fun. I played on the swing, and we had a picnic. We also saw a lot of birds.