1. A NUMBER VS THE NUMBER
As a stand-alone word and as a collective noun, "number" can take a singular or a plural form.
e.g. Two hundreds persons were at the party; the number(s) is (are) just astounding.
However, when preceded by an article and followed by preposition "of", "number" is singular and the verb that follows "number" will be conjugated singular or plural depending on whether there is a definite or indefinite article in front. The expression 'the number of . . .' is singular, while 'a number of . . .' is plural.
Example: The number of people has increased
A number of people have gone
The following sentences are both correct:
The number of bad movies showing this summer is unbelievable.
A number of my friends are going to the beach this weekend
2. GRATER THAN VS MORE THAN
Greater than is appropriate when describing numbers alone.
- “Greater than 100…”
More than should be used when describing the numbers of objects or when making comparisons.
-“More than 100 fish.”
3. NONE VS NO ONE
None can be singular or plural.
No one is always singular
Indefinite pronouns by definition reference nonspecific things or people. Most of these pronouns take a singular verb, some are always plural, and a few may be either singular or plural. Take a look at the lists below, and you'll notice that most indefinite pronouns are singular.
Singular: another, anybody, anyone, anything, each, either, everybody, everyone, everything, many a, neither, no one, nobody, nothing, one, other, somebody, someone
Plural: both, few, many, others, several
Singular or Plural: all, any, none, some, such
A good rule of thumb is to treat most indefinite pronouns as singular and try to remember the few exceptions.
Another very important thing is to think of these pronouns as not one, and that will quickly resolve the issue.
Example 1: Neither of the attorneys (was/were) available for comment.
Think: Not one of the attorneys was available for comment. (singular subject/singular verb)
Example 2: None of the documents (is/are) identified in the brief.
Think: Not one of the documents is identified in the brief. (singular subject/singular verb)
Example 3: Some of the arguments (was/were) weak.
Think: More than one of the arguments were weak. (plural subject/plural verb)
4. AMONG VS BETWEEN
The simple rule will rarely fail you: use between for two things, among for more than two.
5. IT’S VS ITS
There's no handy short cut; all you can do is memorize the rule. It's with an apostrophe means it is; its without an apostrophe means belonging to it.
6. LESS VS FEWER
Less means "not as much"; fewer means "not as many." You earn less money by selling fewer products; you use less oil but eat fewer fries. If you can count them, use fewer.
Use fewer with objects that can be counted one-by-one.
Use less with qualities or quantities that cannot be individually counted.
Incorrect: There were less days below freezing last winter.
Correct: There were fewer days below freezing last winter.
(Days can be counted.)
Correct: I drank less water than she did.
(Water cannot be counted individually here.)
When referring to time or money, less is normally used even with numbers. Specific units of time or money use fewer only in cases where individual items are referred to.
Examples: I have less than an hour to do this work.
I have less time to this work.
I have less money than I need.
I have less than twenty dollars.
He worked fewer hours than I did.
The only occasion in which you might say, "I have fewer than twenty dollars," would be when you were talking about specific dollar bills or coins, such as "I have fewer than twenty silver dollars in my collection."
7. WHICH THAT AND WHO (This is tricky one so pay attention)
Use which for parenthetical remarks and asides (nonrestrictive clauses). Such remarks are not essential to the meaning of the sentence and can be omitted without losing the sense of the sentence. Nonrestrictive clauses are set off by commas.
Use that for clauses that limit or define (restrictive clauses). These clauses are necessary to the meaning of the sentence. You can omit that in a sentence, but don't leave it out if there's any possibility of confusion.
When referring to a person, use who rather than which or that.
Which, that, and who are not interchangeable. Which usually refers to things, that to either things or people, and who to people. When you can replace that with who, do so. Other life forms take that. But how should you refer to a dog with a personality? There are always exceptions.
Let's look at some examples:
The wagon, which [incidentally] is now broken, was purchased at a home improvement store.
The clause which is now broken can be omitted without disrupting the meaning of the sentence. It is not essential to the sentence (nonrestrictive). It's simply additional information.
The wagon that is broken was purchased at a home improvement store.
This one particular wagon is broken; others are not broken. The clause that is broken restricts the meaning of wagon to the one that is in disrepair (restrictive).
The brochure, which was designed by our marketing department, won high praise at the meeting.
The nonrestrictive clause which was designed by our marketing department provides parenthetical information and can be omitted without destroying the meaning of the sentence.
The brochure that was designed by our marketing department won high praise at the meeting.
Notice how in the thrust of the sentence changes for 'brochure' to 'marketing department' as 'which' is changed to 'that'
The marketing department brochure was a winner; the brochures designed by other departments did not win kudos.
The attorney, who graduated from Yale, filed the motion with the court yesterday.
The clause adds parenthetical information (nonrestrictive).
The attorney who graduated from Yale filed the motion with the court yesterday.
It was specifically the Yale graduate who took action rather than the Harvard graduate (restrictive).
The teachers, who have educated my son, deserve an award for patience.
This nonrestrictive clause refers to all of the teachers your son has had in his school career.
The teachers who have educated my son deserve an award for patience.
You are now referring to only the more effective of your son's teachers; other teachers may not have had an impact (and were probably not as patient with your son).
8. COMPARED TO VS COMPARED WITH
To show comparison between unlike things, ‘compare to’ is used. To show comparison between like things, ‘compare with’ is used.
He compared her to a summer day.
Scientists compare the human brain to a computer. (Unlike thing)
The police compared the forged signature with the original. (Like things)
There are two rules which you should consider. First read the usage notes from dictionary.com:
Compare usually takes the preposition to when it refers to the activity of describing the resemblances between unlike things:
He compared her to a summer day.
• Scientists sometimes compare the human brain to a computer.
Compare takes with when it refers to the act of examining two like things in order to discern their similarities or differences:
• The police compared the forged signature with the original.
• The committee will have to compare the Senate's version of the bill with the version that was passed by the House.
When compare is used to mean “to liken” (one) with another, with is traditionally held to be the correct preposition:
That little bauble is not to be compared with (not to) this enormous jewel. But “to” is frequently used in this context and is not incorrect.
Rule 1: Compare to compares unlike things, whereas compare with compares like things.
Rule 2: Compare to is used to stress the resemblance. Compare with can be used to show either similarity or difference but is usually used to stress the difference.
There is a difference between compare to and compare with;
the first is to liken one thing to another;
the second is to note the resemblances and differences between two things.
9. IF VS WHETHER
Use if for a conditional idea, whether for an alternative or possibility.
Thus, Let me know if you'll be coming means that I want to hear from you only if you're coming.
But Let me know whether you'll be coming means that I want to hear from you about your plans one way or the other.
1. Whether is correct when you're discussing two options (whether to get chocolate or strawberry ice cream) and if is correct for more than two options (if she should get ice cream, frozen yogurt, or a cookie).
On the GMAT, whether will (almost) always beat if
Incorrect: Her client didn’t tell her if he had sent his payment yet.
Correct: Her client didn’t tell her whether he had sent his payment yet.
10. AMOUNT VS NUMBER
Amount should be used to refer to quantities that cannot be counted or cannot be expressed in terms of a single number.
Example: "Repairing the Edsel took a great amount of work."
Number is used for quantities that can be counted.
Example: "A large number of deer ate the corn."
11. LIKE VS AS
As and like are used in a number of different ways and can be different parts of speech.
'as' and 'like' - prepositions
As refers to something or someone's appearance or function.
'Before I became a teacher I worked as a waiter.'
'I'm going to the fancy dress party as Superman.'
'The sea can be used as a source of energy.'
The expression 'I've been working as a dog' sounds unusual because it suggests that you were doing the work of a dog!
Like has the meaning 'similar to' and is used when comparing things. Look at these examples:
'I’ve been working like a dog.'
'She looks a bit like her brother.'
'Just like you, I’m always a bit wary of large dogs.'
The expression 'I've been working like a dog' is idiomatic and means that you have been working very hard. Note that we can use adverbs of degree, such as just, very, quite, not much, not at all, a bit, etc, to modify like:
'He’s very serious – not at all like his father, perhaps more like his mother at times.
'as' and 'like' - conjunctions
As and like can also be used as conjunctions:
As means 'in the same way that'. Consider the following:
'I always drink tea without milk, just as they do on the continent.'
'Try to keep your balance on the tightrope, as I do, by spreading out your fingers like this.'
'The first ten days of July were very wet this year, as they were last year and the year before.'
In informal English, like is used in the same way. This is particularly common in American English. Consider the following:
'Nobody else would look after you like I do, baby!'
'She needs the money, like I do, so she works in a bar in the evenings.'
'I hope you’re not going to be sick again, like you were when we went to Brighton.
12. BECAUSE VS IN THAT
One should also be aware of the difference between because and in that. First, using pure strategy, when a question has both because and in that, the answer is most likely in that. Second, because is used to express a simple causal relationship whereas in that qualifies the previous statement.
Look at these examples:
Cause and effect relationship: I went to sleep because I was tired. ==> Being tired caused me to go to sleep.
Qualification: Going to college is a sacrifice in that doing so requires several years of forgoing the income that students could have earned had they not attended college. ==> Going to college is a sacrifice, BUT NOT IN EVERY WAY; there are many ways in which going to college is NOT a sacrifice, but in this sentence, I want to express one way in which going to college IS a sacrifice.
In our SC, "in that" is more precise than "because." "because" is actually wrong in this sentence, but a lot of people adamantly believe that it is correct, so instead of explaining why "because" is wrong, we will stick to why "in that" is better.
13. CAN VS COULD
A): to describe ability/willingness to do something now or in the past.:
e.g. Bill can drive a car very well. - ability
Marcel can play the piano at the party - willingness now
My parents could play golf twenty years ago - ability past
Bill could take photographs until he lost his camera - willingness past
B: to give an explanation or ask for permission:
e.g. In England, you can drive a car at the age of seventeen. - explanation
Can Mary use your computer, this evening?
C: to express perception with certain verbs by using can in the present tense, and could in the past tense. The verbs are: to feel, hear, see:
e.g. Bill and Mary can see the River Seine from their house.
Derek could hear the church bells every Sunday morning when he lived in Milan.
Ann can feel the heat of the sun before she sees it.
D: to explain a possibility and to make a suggestion in the present and future tenses by using could:
e.g. The old table could be in the garage - present
We could go to the cinema next Sunday - future
Could Mary help you to make this dress? – present
14. NOT/BUT VS RATHER THAN
The key here is to realize that not... but... is conjunction. We use conjunctions when we want to join things that are "linguistically equivalent." Help much? No, probably not.
How about some examples?
§ Pucci is not a dog but a cat.
§ Not Todd but Taka will be studying with us today.
§ I not was sad but happy to learn that Megumi was moving to Paris for a better job.
You should notice that the words in bold are "linguistically equivalent," or, as we say in class, "parallel." Now compare one of these sentences if I try to use rather than:
§ Pucci is a cat rather than a dog.
Doesn't this sentence sound crazy? It should; the meaning is all wrong. Now, let's look at a similar sentence, one in which rather than is okay:
§ I want a cat rather than a dog.
This sentence is okay because we are expressing a preference for one thing over another thing.
I need X, not Y = I need X but not Y = I need not Y but X
"I need X rather than Y" does not connote "I need not Y", it just tells your preference.
15. SO VS SO THAT
When used with the meaning in order that, so is usually followed by that
Example : I am saving money so that I can buy a bicycle.
16. MAY VS MIGHT
A: to express a possibility/make a suggestion at the present time or in the future.
Example: If you return tomorrow, you may see Mr Smith.
If you return tomorrow, you might see Mr Smith.
It may rain on Thursday or it might snow.
Might suggests less certainty than may.
B: to give/ask for permission by using may:
Example. The workers may leave at six o'clock if they have finished their work. - give permission
May I see you tomorrow? - ask permission