This sentence contains no errors. The phrase "string, woodwind, and keyboard" describes exactly what types of instruments Kim has mastered. A colon is used when joining two clauses when the second clause explains something in the first one - the second phrase does exactly that (it does not matter that it is not an independent clause). The correct choice is, "various types of instruments: string, woodwind, and keyboard."

This sentence contains no errors. It joins two independent clauses with the use of the coordinate conjunction "but," so a comma should appear before the "but." Otherwise, there is no need for punctuation since all the other options simply split up existing clauses for no logical reason. The correct choice is, "Dennis usually sang in order to relieve stress, but this technique did not seem to work as well anymore."

This sentence contains no errors. This sentence is a simple sentence, so there is no need for punctuation whatsoever: there is only one clause. Commas do not come before prepositions (before) or split verbs. The correct choice is, "Joanna always preferred to compare as many different options as possible before making a purchase. "

This sentence contains no errors. The phrase "Though Colin followed all of the instructor's directions" is an example of an introductory phrase, explaining information necessary to the context of the sentence, but outside of the main sentence, grammatically. These types of phrases must be followed by a comma in order to separate them from the rest of the sentence. Furthermore, "him" is the appropriate word after the word "to," because it is acting as the object of the preposition ("he" must always be the subject of its clause). The answer is, "all of the instructor's directions, he could not get the boomerang to return to him."

This sentence contains no errors: the pronouns are appropriate. Since "she" and "I" are the subject of the sentence, they should not be changed to "her" or "me," which are used when the pronoun is the object. The correct choice is, "She and I went."

This sentence contains no errors. The phrase "Even though it is not directly related to many fields" is an example of an introductory phrase, explaining information necessary to the context of the sentence, but outside of the main sentence, grammatically. These types of phrases must be followed by a comma in order to separate them from the rest of the sentence. Choices with "philosophy is viewed" is incorrect because of the use of passive voice. The correct choice is, "related to many fields, many view philosophy as an important subject of study."

This sentence contains no errors. It combines two related independent clauses without the use of a conjunction. When this occurs, a semicolon should be used. Note that a colon is inappropriate because the phrase "he had a knack for finding items with hidden value" does not exactly explain why he bought things from flea markets, specifically. He could easily acquire things with value in other places. It is clear, however, that these phrases are related somewhat, so a semicolon is the most appropriate punctuation to use.

Also note that "had" would be inappropriate in the second clause because that would imply that Kenneth is no longer around (i.e. no longer selling, dead, etc.), which is inconsistent with the implications of the first clause in this sentence (that he is actively buying). The correct choice is, "store from thrift shops and flea markets; he has a knack for finding items with hidden value."

This sentence contains no errors. It joins two related clauses with a colon because the second clause explains something about the first clause: the specifics of Shaun's ritual. Furthermore, the phrases "he would sit in the back corner of the local coffee shop, listen to music, and type for hours" are parallel actions, so they should be separated by commas in order to show that they are each distinct actions in his ritual. The correct choice is, " when he wrote: he would sit in the back corner of the local coffee shop, listen to music, and type for hours."

This sentence contains no errors. The phrase "instead of physical books" is an example of a parenthetical expression: a phrase that explains more about a particular word or phrase in the sentence, but is not introduced by a relative pronoun. These phrases must be introduced and completed with a comma in order to separate them from the main clause of the sentence. The correct choice is, "preferred eBooks, instead of physical books, because they saved space."

There are no errors in this sentence. This is a simple sentence and the word "exhausted" is not part of a verb (and therefore is not passive voice); it is an appositive adjective, joined to the word "Tom" by the linking verb "is." The other sentences contain errors in punctuation, are incomplete, or wordy. The correct choice is, "Tom is exhausted after a long day of work."