I have already written about some grammar questions that are typical for the SAT Grammar (or Verbal) section. In this entry, I am going to focus on the Rules of Punctuation, especially on the difference between a semi-colon and a colon.

Actually, the difference between a semi-colon (;) and a colon (:) is relatively simple. The only thing you need to remember is that semi-colon separates two independent sentences. in fact, semi-colon serves the same purpose as a period but is “weaker.” As for the colon, it usually serves as a warning that the next part of the sentence is either an explanation of or an addition to the first one. A colon can be used to separate two independent sentences or to precede a list of items, a quotation, or an expansion or explanation.

Here is an example of the punctuation problem in a way how it can appear on the SAT grammar (language) section:

It took me by surprise, then, when my favorite exhibit at the museum was one of it’s tiniest; the Thorne Miniature Rooms.

Here are your choices:

a) NO CHANGE

b) its tiniest;

c) its tiniest:

d) it’s tiniest,

In this particular example we have to deal with two types of grammar mistakes, one of which is a punctuation error. I hope that the first mistake is obvious although the confusion between it’s and its is not that uncommon. If you remember that its is a pronoun while it’s is a compressed form of it is, you can easily cross (a) and (d). Now we have to face a punctuation problem and recall the difference between a colon and a semi-colon. Since a semi-colon is used in place of a period to separate two independent sentences, (b) cannot be the right answer. Circle the only one left – (c) – and proceed with your test.