I am looking for a english language school in san francisco where I will be for 2 months. I am looking for general English course.
I went to Embassy English and it's a well equipped school with smart boards. I also took the General English course and ended up adding some Intensive courses. They're quite flexible and will help you find the right course.
What I liked the most is that they make the lessons fun because we also play games to help review the lesson.
Also great was the location, very central on Market Street in Union Square.
Some more schools that offer General English courses:

Advance English Academy
American Academy of English
ilsc Language Schools
intrax English School

Let me know if you would like me to list some more.