One of the trick questions more difficult to detect on the SAT / ACT is on the subject of comparisons. This is because you've probably never explicitly been taught this small point, and you don't know what to look for.
What can be legitimately contrasted?
When making a comparison, the elements being compared must be of the same form. This means two things:
1) The elements should be of the same word type, grammatically.
Nouns should be compared to nouns: 'He eats fish more often than rice'.
Infinitive verbs should be compared to infinitive verbs: 'They prefer to sleep, rather than walk.'
Progressive verbs should be compared to progressive verbs: 'They were singing more than they were eating.'
To illustrate, the alternative sentence, 'They were singing more than they ate', would be grammatically problematic. It utilizes a progressive verb for the first element being compared, and an infinitive verb for the second.
2) The elements should be counterparts: two things that could reasonably be compared.
Let me illustrate.
'He watches more comedies than dramas.'
The things being compared are comedies and. dramas. They're both genres of movies.
'They spend more time playing sports, than doing homework.'
Both 'playing sports' and 'doing homework' are ways of spending one's time.
'At the party I want to dance, enjoy the food, and spend time with my friends, rather than be miserable.'
Sentence 3 does not compare corresponding elements. The first three things - "dance", "enjoy the food", and "spend time with friends" are activities one might reasonably do at a party. The thing being contrasted with these three, "be miserable", is an emotion. This, in spite of the fact that all three things being compared use the same grammatical form: infinitive verbs, with modifiers.
Though this is a sentence which could easily be used in the everyday vernacular, it would probably be considered suboptimal on the SAT / ACT.
The contrast principle is similar to that of parallel structure. If you wish to understand the issue further, I'd recommend looking at that article after.
The comparison vocabulary
There are certain words that indicate comparison. Some of them are listed below:
words with than: more than, less than rather than, slower than, happier than
in relation to, relative to
Oftentimes, the two elements being compared will be directly before and after the comparison words. For example, in the sentence 'I prefer to walk rather than run in the mornings', the two elements being compared are 'walk' and 'run'. They are respectively before, and after, the comparison words 'rather than.'
Note that this is not a comprehensive list, and there can certainly be other words or phrases indicating comparison or contrast that aren't listed here. Just keep an eye out for any words indicating that a comparison is being made.
A comparison word, in fact, doesn't have to be given at all. Take the following sentence:
'The event should be celebrated, not criticized.'
'Not' serves as the comparison word in this sentence, but it's too general to put on the list.
What form should the phrase be changed to?
When a comparison question is given on the SAT / ACT, one element of the comparison will be underlined and the other won't. The section of the comparison which is not underlined - and therefore, can't be changed - is the one which determines the element's form.
For example, in the sentence:
"I like oranges more than I like eating apples", the two things in the sentence being compared are "oranges" and "I like eating apples." (The things before and after the comparison words "more than.")
The element which isn't underlined is "oranges," so that determines the correct form of the other item. "Oranges" is a noun, so "I like eating apples" also has to turn into a noun. An appropriate replacement would be simply "apples."
Alternatively, you could say that the two things being compared are "I like oranges" and "I like eating apples". Since "I like oranges" isn't underlined, you'd have to changes the "I like eating apples" to "I like apples." (without the progressive verb 'eating.')
Therefore, either of the following two sentences would be considered of higher quality on the SAT / ACT, than the original sentence:
"I like oranges more than apples."
"I like oranges more than I like apples."
Below are a few examples to illustrate the point:
Young boys need encouragement and support, rather than to be rebuked, when their behavior doesn't match one's vision of ideal comportment.
A) NO CHANGE
B) rather than rebuke,
C) rather than to be rebuked
D) rather than to have been rebuked,
(Note for those unfamiliar with how SAT Writing & Literature / ACT English questions are presented:
All, or part of, a sentence in the passage is underlined. Of the answer options, you're meant to pick the answer option which, when inserted in place of the underlined section, would make for the highest quality English. On the ACT English section, there will be a question before the options: 'Choose the best answer.' The SAT simply presents the options, without a question beforehand.)
The two elements being compared (the elements before and after 'rather than') are 'encouragement and support' and 'to be rebuked.' The non-underlined element is 'encouragement and support', so that determines the correct form of the other element. Both 'encouragement' and 'support' are nouns; the other element must be in noun form as well.
The only option which offers a noun is B), 'rather than rebuke.' 'Rebuke' here is in its noun form, not verb form, in opposition to the other three options. The answer is B).
The man was happy, relative to how much suffering he'd endured.
A) NO CHANGE
B) how he'd felt a year ago.
C) how he'd suffered beforehand
D) his suffering
Here, the things being compared are 'the man was happy' and 'how much suffering he'd endured.' This is linguistic nonsense. One is an independent clause, detailing how the man feels. The other is a noun: 'how much suffering' is a thing, synonymous with 'the scale of his suffering'. (In this clause, 'he'd endured' is a descriptor of 'how much suffering', rather than a subject + predicate.)
Had the words 'relative to' been replaced by a phrase like 'taking into account', or 'considering', the sentence would have been fine. In that case, the sentence wouldn't have contained a comparison. Because these phrases are sometimes used interchangeably, the sentence in its current form may sound grammatically correct to your ear. It's not.
If the first element is 'The man was happy', we must consider what a reasonable counterpart would be. In this case, it's either a person - 'The man was happy, relative to his sister' - or another point in time. The only option which fits is B: 'The man was happy, relative to how he'd felt a year ago.'
Compared to the formal atmosphere in most finance firms, employees of high tech companies tend to conduct themselves more casually.
A) NO CHANGE
B) employees of high tech companies tend to be more casual.
C) employees of high tech companies, tend to conduct themselves more casually.
D) the atmosphere in high tech firms tends to be more casual.
This example is a little different, because the comparison word isn't between the two elements , but rather at the beginning of the sentence ("compared to"). A comma now separates them instead. The two elements are "the formal atmosphere in most finance firms" and "employees of high tech firms tend to conduct themselves more casually."
The non-underlined element is the first one, "the formal atmosphere in most finance firms." The underlined element should be its counterpart; that is, the casual atmosphere in high tech firms. The only appropriate option is D).
The original sentence is problematic because a comparison is made between an atmosphere of one company type, and employees of another. These don't work together.
If there appears to be a question type where the issue is unclear, and it contains some kind of comparison word - either one of those listed above, or some other obvious comparison - check if the two elements work together. If they don't fit grammatically and / or logically, you may just have the key to your answer.
For more tips and methods, or to get help personally tailored to your needs, consider working with me. I've helped people from all over the world get into their dream school. Studying privately with a skilled teacher is the best way to increase your test score, and in coaching you, I adopt my methods specifically to your personality, schedule, and learning style.