"The thief evaded authorities for a long time because he conducted himself as though he was a bank teller." - This sentence contains one error. When describing hypothetical or untrue situations the subjunctive verb mood, in this case "were," is required.

"The thief evaded authorities for a long time because he conducted himself like he was a bank teller." - This sentence contains two errors. When describing hypothetical or untrue situations the subjunctive verb mood, in this case "were," is required. Additionally, it is better to use "as though" rather than "like" in this situation. "Like" is better used when placed right next to an active verb, is in: "he acted like a bank teller."

"The thief evaded authorities for a long time because he conducted himself like as if he was a bank teller." - This sentence contains two errors. When describing hypothetical or untrue situations the subjunctive verb mood, in this case "were," is required. Additionally, "like as if" is repetition therefore redundant and improper diction.

"The thief evaded authorities for a long time because he conducted himself as if he was bank teller." - This sentence contains two errors. When describing hypothetical or untrue situations the subjunctive verb mood, in this case "were," is required. Also, the sentence is missing an indefinite article before "bank teller."

"The thief evaded authorities for a long time because he conducted himself as though he were a bank teller." - This sentence has no errors. 

"Some scientific discoveries serve specific purposes for those researchers which desire to gain knowledge from them." - This sentence contains an error. "Which" is the improper pronoun for "researchers." Because researchers are, in fact, people, the correct pronoun is "who."

"Some scientific discoveries serve specific purposes for those researchers that desires to gain knowledge from them ." - This sentence contains two errors. "Which" is the pronoun for "researchers." Additionally, there is a Subject-Verb agreement error. "Researchers" is plural, but "desires" fits with singular subjects.

"Some scientific discoveries serve specific purposes for those researchers who desire they gain knowledge from them." - This sentence contains a diction error; "they gain knowledge from them" is improper diction, as it is unnecessary and imprecise.

"Some scientific discoveries serve specific purposes for those researchers who desire about knowledge to be gained." - This sentence contains one error. To "desire about" is an improper idiom. 

"Some scientific discoveries serve specific purposes for those researchers who desire to gain knowledge from them." - This sentence has no errors. 

"Athletes who train sporadically achieve poor results in competition." - Includes a kind of ambiguous modifier error sometimes called a squinting modifiers. Squinting modifiers occur when a word is placed in a sentence such that the modifier could apply to both parts of the sentence. In this case it is not clear if "athletes" who do not train consistently "achieve poor results in competition," or if "athletes who train" in general only "sporadically achieve poor results in competition." Often, sentences with squinting modifiers need to be reframed, so as to put the modifier clearly beside the element of the sentence it modifies.

"Athletes what train sporadically achieve poor results in competition." - This option includes the same ambiguous modifier error as previously discussed, and makes the additional error of incorrectly replacing "who" with "what." Athletes are people, and therefore "who" is correct in this instance.

"Athletes who train; sporadically achieve poor results in competition." - This option does not feature the same ambiguous modifier, as in this instance "sporadically" must modify the frequency with which "poor results" are achieved; however, this sentence incorrectly uses a semicolon, creating two sentence fragments.

"Athletes: who train sporadically poor results achieve in competition." - This sentence incorrectly uses a colon after just a proper noun. Colons must be preceded by a full independent clause.

"Athletes who train sporadically tend to achieve poor results in competition." This option has no errors. It is the most correct and precise re-framing of the example sentence. Inserting "tend to" effectively separates the modifier "sporadically" from the part of the sentence it does not modify, without altering the meaning of the sentence too significantly.

"Stopping as fast as he could, Jim's car narrowly avoided hitting the pedestrian." This sentence includes a dangling-modifier. "Stopping as fast as he could" logically refers to Jim; however, the subject of the second sentence is "Jim's car." Since intent is ascribed to the stopping, it logically stands that the best way to fix this problem would be to make Jim the subject of the main clause.

"Jim's car avoided, quite narrowly, the hitting of the pedestrian." - This option fails to rectify the dangling-modifier, and also adds confusing, incorrect, and imprecise verbiage to the main clause.

"the car that belonged to Jim narrowly avoided hitting the pedestrian." - This option again fails to rectify the dangling-modifier, it also introduces the unnecessary and awkward "the car that belonged to Jim" construction.

"the car narrowly avoided hitting the pedestrian." - This option eschews mention of Jim entirely, thus creating an inconsistency with the first clause, which contains the pronoun "he."

"hitting the pedestrian was avoided by the car." - This option still includes a dangling modifier, and re-phrases the main clause unnecessarily and confusingly.

"Stopping as fast as he could, Jim narrowly avoided hitting the pedestrian with his car." - This is the correct version of the example sentence.

"Happily, Ronald's boss asked to meet with Ronald after work." - This sentence features an unclear, or ambiguous, modifier. Since the main clause is talking about two people, Ronald and his boss, it is unclear, in this situation, to whom the modifier "happily" applies. Is it a happy occurence for Ronald, or does "happily" describe his boss' manner when asking the question? In cases where two people are being discussed, and one of them described, it is best to be as clear as possible about who is being described.

"Happily Ronald's boss asked to meet with Ronald after work." - This option still includes an ambiguous modifier, and, additionally, misses a comma after the introductory phrase "happily."

"Ronald's boss asked to meet happily with Ronald after work." - This option moves the modifier into the main body of the sentence, but does little to make that modifier less ambiguous.

"Happily; Ronald's boss asked to meet with Ronald after work." - This option, once again, does not clear up the dangling modifier, and makes a sizeable error of punctuation by using a semicolon to incorrectly separate a dependent clause. 

"Happily for Ronald, his boss asked to meet with him after work." - This option correctly addresses the modifier ambiguity.

"Relieved that the election was finally over, the governor's celebratory dinner was incredibly lavish." - This option is incorrect due to a dangling modifier. The first clause, "relieved that the election was finally over," refers to "the governor," therefore "the governor" must be the subject of the second clause, rather than the celebratory dinner (which, since it is not, to our knowledge, sentient cannot feel relief, nor even the stress that would precede such relief). 

"Relieved and celebratory that the election was over, the governor's dinner was incredibly lavish. " - This option includes creates the same dangling modifier as did the previous option, alters the meaning of the sentence, and incorrectly uses "celebratory" as an adjective describing a mood (it would be correct to say "feeling celebratory").

"Relieved that the election was over; the governor's celebratory dinner was incredibly lavish." - This option keeps the same dangling modifier error, while adding a semicolon error. The first clause of this sentence is a dependent clause and therefore cannot be separated from the main clause with a semicolon.

"Relieved that the election was over, he the governor's celebratory dinner was lavish." - While still repeating the dangling modifier error, this opiton also unnecessarily, and confusingly adds the pronoun "he" to the main clause, even thought "the governor" is a clear and obvious label for the subject.

The correct version of this sentence reads: "Relieved that the election was finally over, the governor held an incredibly lavish celebratory dinner." - Making the governor the subject of the main clause is the best way to fix this dangling modifier.

The example sentence includes a dangling modifier. The introductory phrase "Traveling by plane," must be immediately followed by the subject that was, in fact, traveling by plane. Only two of the provided options correct this dangling modifier error. Of those two it is more concise, and clear, to say "we saw roads and highways that looked like thin, winding chords," rather than "we saw, like thin winding cords, the roads and highways."

In this sentence, the section that modifies the subject—“unlike the modern model of the atom”—must proceed the main clause, rather than succeed it. "Unlike the modern model of the atom, the Bohr model states that electrons travel in fixed paths around the nucleus," fixes the problem.

In the sentence above, as it is written, it is not clear what the modifying phrase "After he returned from the long walk" is referring to. A chair cannot walk. In order to avoid a dangling modifier, a subject which can be appropriately modified by such a phrase must be included. The best way to change the underlined portion of the sentence above is: "the man settled into the chair on the porch."

The sentence above contains an example of a squinting modifier. It is not clear if the word "always" is meant to modify how often the young people listen to their elders, or how often they end up in trouble. This error must be corrected by changing the position of the modifier. The best way to correct the underlined portion of the sentence above is: "Young people who don't always listen to their elders wind up in trouble."