There should be a comma after breakfast instead of a semicolon. "Since he is so big," is not a complete grammatical clause.

The sentence is correct and the semicolon is correctly positioned, since it separates two independent clauses. A semicolon is an optional stylistic choice here, separating the clauses with a comma and a coordinating conjunction or a period would be equally correct.

The word "moment" should be followed by a colon, not a semicolon. This is because semicolons should only be used to separate two independent clauses that could stand alone as two different sentences, which is not the case here. A colon here would correctly grammatically signal the beginning of the list.

Semicolons may be used to separate two related, independent clauses; however, they must be used alone, and without any accompanying conjunction. The sentence above incorrectly places the coordinating conjunction "and" after the semicolon. Replacing the semicolon with a comma, or deleting the coordinating conjunction would both grammatically correct this sentence. The best way to correct the underlined portion above is, I need to go to the dry cleaners; I also need to go and pick up some flowers for my wife.

Semicolons may be used to separate two related, independent clauses; however, they must be used alone, and without any accompanying conjunction. Commas with a conjunction and a semicolon are both grammatically correct options to join two independent clauses into one compound sentence; whichever you choose is a matter of personal writing style. The best way to correct the underlined portion above is, Emmett is one of the rudest human beings I have ever met, but I can't deny that he's a fascinating conversationalist when he wants to be.

Semicolons may be used to separate two related, independent clauses. Note though that semicolon must be used alone, and without any accompanying conjunction. The best way to correct the underlined portion above is, "Francois always struck me as a smarmy chap; several people seem to like him."

Semicolons link two independent clauses; the phrase "but now John was thinking of cutting it down" is not an independent clause. The use of "but" makes it dependent on the first clause, and means that a comma is more appropriate. Note that coordinating conjunctions should never follow semicolons.

When introducing a list, a colon or a comma should be used (eg. "...in their jurisdictions: Montana..."). Semicolons are generally used to link two independent clauses in a sentence.

Semicolons may be used to separate two related, independent clauses; however, they must be used alone, and without any accompanying conjunction.  The portion of the sentence that needs to be corrected in the sentence above is, "noise; and." The required correction is simply to delete the coordinating conjunction "and."

In the example sentence "If you don't stop lying to the police" acts not as an independent clause, but rather as a dependent introductory clause. Thus, the semicolon must be replaced with a comma in order for this sentence to be grammatically correct.