About subject-verb agreement

Today, I solved the exercises in

http://grammar.ccc.commnet.edu/grammar/sv_agr.htm

If you remember, it is one of the optional tasks in the writing course. It was very interesting because there are many examples, in addition to those we saw in classroom, that clarifies more this grammar topic.

I want to cite the main idea of subject-verb agreement in the website: "Basic Principle: Singular subjects need singular verbs; plural subjects need plural verbs.".

In support of this, there are in this site ten rules with examples where this principle applies.

But also, there are three interesting quizes (the homework). The first one, the quiz is fill in the blank space style, there are two choices. The second one, the same fill the blank space but with an explanation of the right choice; and the third one contains a reading text where you can select in some paragraphs the right choice that corresponds with the subject-verb agreement. In my personal opinion, the reading text is interesting because talks about why people in United States don't approve or like soccer (football soccer), as in Mexico or other countries, and also compares soccer with other sports in USA using examples and contrasting them. You should look for it!!