We use # to show example stenances

1. Place a comma before a counjunction introducing an independent clause

# The situation is perilous, but there is still one chance of escape.

1.1 If a dependent clause, or an introductory phrase requiring to be set off by a comma, precedes the second independent clause, no comma is needed after the conjunction.

# The situation is perilous, but if we are prepared to act promptly, there is still one chance of escape.

1.2 When the subject is the same for both clauses and is expressed only once, a comma is useful if the connective is but, the comma should be omitted if the connective is and.

# I have heard the arguments, but am still unconvinced.

# He has had several years’ experience and is thoroughly competent.

2. Do not join independent clauses with a comma

2.1 Use semicolons or periods intead of commas to connect two grammatically complete clauses.

# It is nearly half past five; we cannot reach town before dark.

# It is nearly half past five. We cannot reach town before dark.

2.2 If a conjunction is inserted, the proper mark is a comma

# It is nearly half past five, and we cannot reach town before dark.

2.3 If the second clause is preceded by an adverb, such as accordingly, besides, then, therefore, or thus, and not by a conjunction, the semicolon is still required.

# I had never been in the place before; besides, it was dark as a tomb.

3. Use a colon after an independent clause to introduce a list of particulars, an appositive, an amplification, or an illustrative quotation.

# Your dedicated whittler requires: a knife, a piece of wood, and a back porch. [Wrong]

# Your dedicated whittler requires three props: a knife, a piece of wood, and a back porch. [Correct]

# Understanding is that penetrating quality of knowledge that grows from: theory, practice, conviction, assertion, error, and humiliation. [Wrong]

# Understanding is that penetrating quality of knowledge that grows from theory, practice, conviction, assertion, error, and humiliation. [Correct]

4. The number of the subject determines the number of the verb.

4.1 Words that intervene between subject and verb do not affect the number of the verb.

# The bittersweet flavor of youth-its trials, its joys, its adventures, its challenges-are not soon forgotten. [Wrong]

# The bittersweet flavor of youth-its trials, its joys, its adventures, its challenges-is not soon forgotten. [Correct]

4.2 A common blunder is the use of a singular verb form in a relative clause following “one of…” or a similar expression when the relative is the subject.

# One of the ablest scientists who has attacked this problem [Wrong]

# One of the ablest scientists who have attacked this problem [Correct]

# One of those people who is never ready on time [Wrong]

# One of those people who are never ready on time [Correct]

5. Use a singular verb form after each, either, everyone, everybody, neither, nobody, someone.

# Everybody thinks he has a unique sense of humor.

# None of us is perfect.

5.1 A plural verb is commonly used when none suggests more than one thing or person.

# None are so fallible as those who are sure they’re right.

6. A compound subject formed of two or more nouns joined by and almost always requires a plural verb.

# The walrus and the carpenter were walking close at hand.

6.1 A singular subject remains singular even if other nouns are connected to it by with, as well as, in addition to, except, together with, and no less than.

# His speech as well as his manner is objectionable.

7. When who introduces a subordinate clause, its case depends on its function in that clause.

# Virgil Soames is the candidate who we think will win. [We think he will win.]

# Virgil Soames is the candidate whom we hope to elect. [We hope to elect him.]

8. A pronoun in a comparison is nominative if it is the subject of a stated or understood verb.

# Sandy writes better than I. (Than I write.)

8.1 In general, avoid “understood” verbs by supplying them.

# I think Horace admires Jessica more than I. [Wrong]

# I think Horace admires Jessica more than I do. [Correct]

# Polly loves cake more than me. [Wrong]

# Polly loves cake more than she loves me. [Correct]

9. A participial phrase at the beginning of a sentence must refer to the grammatical subject.

# Walking slowly down the road, he saw a woman accompanied by two children. [walking refers to he]

# He saw a woman, accompanied by two children, walking slowly down the road. [walking refers to women]

9.1 Participial phrases preceded by a conjunction or by a preposition, nouns in apposition, adjectives, and adjective phrases come under the same rule if they begin the sentence.

# On arriving in Chicago, his friends met him at the station. [Wrong]

# On arriving in Chicago, he was met at the station by his friends. [Correct]

# Young and inexperienced, the task seemed easy to me. [Wrong]

# Young and inexperienced, I thought the task easy. [Correct]