Hope this helps! 
** LONG POST **
GMAT Sentence Correction:
General Principles:
1. Subject-Verb Agreement
2. Style
3. Pronoun
4. Parallelism
5. Idioms
6. Comparison
7. Modifiers
8. Mood, Tense and Voice
1. Subject-Verb Agreement
a. Both must agree in numbers (He likes..., they hate...)
b. Ignore middleman (Hacken Lee, an idol of many teenagers, LIVES happily.) (Centre of all NBA teams IS...)
c. AND vs ADDITIVE PHRASE (e.g. along with...) (Jack and Bill GO ...) (Jack, along with 10 guys, GOES...)
d. OR and NOR (Neither Jack nor Bill LIKES ...) (Neither Jack nor his teams LIKE ...)
e. Collective nouns are singular (e.g. majority, audience) (Kaka's team WINS ...)
f. Indefinite pronouns are usually singular (e.g. everybody, someone) (Anyone WANTS some soup?)
g. THE NUMBER OF vs A NUMBER OF (A number of soldiers MARCH ...) (The number of alphabets IS 26)
h. Subject phrase (A chuck of words contains either subject or verb) (Having a lot of women IS not fun.)
2. Style
a. Eliminate awkwardness
b. Eliminate redundancy
c. Eliminate ambiguity
3. Pronoun
a. Agreement with subject (Investment Bankers have a tough life because (THEY WORK / HE WORKS) for long hours.)
b. Reference (Sally, Janet, Kate and Betty went hiking, (SHE / KATE) had twisted her ankle.)
c. Case (Subject: WHO, Object: WHOM, Possessive: WHOSE) (Murphy and (I / ME) go...)
4. Parallelism
a. Sentence parts must be parellel in order to be gramatically correct.
b. Parallel items should have the same pronouns. (THOSE WHO ARE male and THOSE WHO ARE female.)
c. All verbs shuold be parallel (As a managing director, he is SERVING clients, MOTIVATING subordinates and DEVISING corporate strategy everyday.)
d. Items next to both sides of VERB OF BEING must be parallel. (Jack's TEAM is ELITE)
5. Idioms
6. Comparison
a. A speical form of parallelism
b. Compare like things only (Hank Paulson and Morgan Stanley are leaders of the Wall Street.) <==WRONG!
c. LIKE is for comparing nouns (LIKE Harvard Business School, UV Darden also use the case approach.)
d. AS is for comapring phrases (AS all Ivy League institutions do not offer any sports scholarship, they tend to be less competitive than other big names in NCAA.)
e. Quantity Words for 2 or less items: (e.g. less, better, between...)
f. Quantity Words for more than 2 items (e.g. least, best, among...)
g. Quantity Words for countable items (e.g. fewer, number, many...)
h. Quantity Words for uncountable items (e.g. less, amount, much...)
7. Modifiers
a. ADVERBS modify VERBS, CLUASE, PHRASE or even another ADVERB.
b. ADJECTIVES only modify NOUNS.
c. Keep MODIFERS as close as possible to ITEMS BEING MODIFIED.
d. Modifiers with WHICH are not essential. (2 IFC, which is located in Central, is currently the tallest building in Hong Kong.)
e. Modifiers with THAT are essential. (2 IFC, that is the home of BNP Paribus, is also a home of many financial firms.)
f. Modifiers cannot modify possessive nouns.
8. Mood, Tense and Voice (MTV in short)
a. Always use simple tense, unless the action is ongoing or 2 actions take place in different time are being mentioned.
b. Never spilt infinitives. (You should QUICKLY RUN / RUN QUICKLY to my home.)
c. For subjunctive mood, use plural verb after IF cluase (IF I WERE 7 feet tall, I will be a great basketball player.)
d. When IF clause is not followed by THEN clause, replace IF with WHETHER.
** LONG POST **
GMAT Sentence Correction:
General Principles:
1. Subject-Verb Agreement
2. Style
3. Pronoun
4. Parallelism
5. Idioms
6. Comparison
7. Modifiers
8. Mood, Tense and Voice
1. Subject-Verb Agreement
a. Both must agree in numbers (He likes..., they hate...)
b. Ignore middleman (Hacken Lee, an idol of many teenagers, LIVES happily.) (Centre of all NBA teams IS...)
c. AND vs ADDITIVE PHRASE (e.g. along with...) (Jack and Bill GO ...) (Jack, along with 10 guys, GOES...)
d. OR and NOR (Neither Jack nor Bill LIKES ...) (Neither Jack nor his teams LIKE ...)
e. Collective nouns are singular (e.g. majority, audience) (Kaka's team WINS ...)
f. Indefinite pronouns are usually singular (e.g. everybody, someone) (Anyone WANTS some soup?)
g. THE NUMBER OF vs A NUMBER OF (A number of soldiers MARCH ...) (The number of alphabets IS 26)
h. Subject phrase (A chuck of words contains either subject or verb) (Having a lot of women IS not fun.)
2. Style
a. Eliminate awkwardness
b. Eliminate redundancy
c. Eliminate ambiguity
3. Pronoun
a. Agreement with subject (Investment Bankers have a tough life because (THEY WORK / HE WORKS) for long hours.)
b. Reference (Sally, Janet, Kate and Betty went hiking, (SHE / KATE) had twisted her ankle.)
c. Case (Subject: WHO, Object: WHOM, Possessive: WHOSE) (Murphy and (I / ME) go...)
4. Parallelism
a. Sentence parts must be parellel in order to be gramatically correct.
b. Parallel items should have the same pronouns. (THOSE WHO ARE male and THOSE WHO ARE female.)
c. All verbs shuold be parallel (As a managing director, he is SERVING clients, MOTIVATING subordinates and DEVISING corporate strategy everyday.)
d. Items next to both sides of VERB OF BEING must be parallel. (Jack's TEAM is ELITE)
5. Idioms
6. Comparison
a. A speical form of parallelism
b. Compare like things only (Hank Paulson and Morgan Stanley are leaders of the Wall Street.) <==WRONG!
c. LIKE is for comparing nouns (LIKE Harvard Business School, UV Darden also use the case approach.)
d. AS is for comapring phrases (AS all Ivy League institutions do not offer any sports scholarship, they tend to be less competitive than other big names in NCAA.)
e. Quantity Words for 2 or less items: (e.g. less, better, between...)
f. Quantity Words for more than 2 items (e.g. least, best, among...)
g. Quantity Words for countable items (e.g. fewer, number, many...)
h. Quantity Words for uncountable items (e.g. less, amount, much...)
7. Modifiers
a. ADVERBS modify VERBS, CLUASE, PHRASE or even another ADVERB.
b. ADJECTIVES only modify NOUNS.
c. Keep MODIFERS as close as possible to ITEMS BEING MODIFIED.
d. Modifiers with WHICH are not essential. (2 IFC, which is located in Central, is currently the tallest building in Hong Kong.)
e. Modifiers with THAT are essential. (2 IFC, that is the home of BNP Paribus, is also a home of many financial firms.)
f. Modifiers cannot modify possessive nouns.
8. Mood, Tense and Voice (MTV in short)
a. Always use simple tense, unless the action is ongoing or 2 actions take place in different time are being mentioned.
b. Never spilt infinitives. (You should QUICKLY RUN / RUN QUICKLY to my home.)
c. For subjunctive mood, use plural verb after IF cluase (IF I WERE 7 feet tall, I will be a great basketball player.)
d. When IF clause is not followed by THEN clause, replace IF with WHETHER.
