Although English is your native language, sometimes you may have to admit that its grammar is a lot more complex than it should be.

Boosting your grammar skills before taking the ACT in Orinda will benefit you as you begin answering the English and Reading sections, as well as the optional Essay. Remember that the difficulty of these tests is even more compounded by the time limit, so it goes without saying that brushing up on your English grammar skills is essential.


Many people use pronouns incorrectly, especially in formal writing or writing essays. So it’s no big wonder that the ACT aims to test your knowledge on the proper pronoun-antecedent agreement. In English grammar, it means that the pronoun must match its antecedent in both subject, gender, and number.

1) “John left his phone inside the car.” (The antecedent is “John” which is singular and masculine, so the pronoun is “his”).

2) “John and Mary did their school presentation very well” (The antecedents are “John” and “Mary” which are plural, so the pronoun is “their.”)

3) “Some of the jewels lose their luster” (The antecedent is “Some” which is plural and neutral, so the pronoun is “their.” Don’t be misled by the word “jewels” even though it is placed next to the verb “lose.” The word “jewels” is only an object of the preposition, not the subject.)

Fragments and run-ons

Normally, a sentence has three components:
1) A subject
2) A predicate
3) A complete thought

fragment is an incomplete sentence that lacks any of these three things mentioned above. An example of a fragment would be “to sleep early,” which doesn’t have a subject, a predicate, and a complete thought.

To complete a fragment and make it a sentence, it should be like this: “You should avoid coffee in order to sleep early.” The corrected sentence has a subject (“You”) and a predicate (“should avoid coffee”) as well as a complete thought.

run-on is a grammatically incorrect sentence because two or more independent clauses (complete thoughts) are joined together without the proper use of a conjunction or punctuation. It is also called a “fused sentence.”

“Mary likes to cook, she makes delicious pies every day” is an example of a run-on sentence. It has two independent clauses (“Mary likes to cook” and “she makes delicious pies every day”) which are improperly joined by a comma. Instead of a comma, these two independent clauses should be connected by a conjunction which, in this case, is “and”: “Mary likes to cook and she makes delicious pies every day.”

Subject-verb agreement

If the subject is singular, the verb should also be singular. If the subject is plural, the verb should also be plural. Those are the general rules in the subject-verb agreement.

This may sound easy, right? However, The ACT’s English section often contains long sentences in which the subject and the verb are interrupted by several words, phrases, and clauses. There are other instances of alteration in the sentence or compound subjects. Here are a few examples:

1) “The man with the blue gloves is my father.”
The “man” is the subject, not “gloves,” so the verb should be singular which is “is.” The sentence has a prepositional phrase “with the blue gloves” because it contains the preposition “with” while “gloves” is the object of the preposition.

Always remember that a prepositional phrase should not contain the subject. Tip: cross out the prepositional phrase “with the blue gloves” and you will still be able to identify the subject-verb agreement: “The man (singular subject) is (singular verb) my father.”

2) “In this town reside fifty families”
This sentence also contains a prepositional phrase “in this town” as it has the preposition “in.” Again, a prepositional phrase should never contain the subject. It may sound awkward because the singular noun “town” is next to the plural verb “reside.” But if you try to alter the sentence, it becomes like this:

“Fifty families reside in this town”
If you get the idea that the fifty families (and not the town) do the residing, then you’ll ultimately recognize the correct subject-verb agreement: “reside” is the plural verb for the plural subject “families.”

3) “John and James are going to the movies”
This sentence has more than one subject, which is “John” and “James.” Since “John” and “James” are connected by the conjunction “and,” it makes them plural subjects. Therefore, the verb should be plural — “are going.”


On the ACT, you may encounter two-part idioms such as “not only… but also,” “between… and” “as… as,” “Either… or,” and “Neither… nor.”

There are also many idioms that contain prepositions such as “difference between,” “in connection with,” “interested in,” “opposed to,” “worrying about,” and a lot of others. You can find complete lists of the commonly used ACT idioms on the Internet and use them for reference.

Parallel Structure

Parallel structure means that the phrases or elements should be in the same grammatical form. You can confirm this by comparing the parts of speech such as nouns, verbs, and prepositions.

See this example with an error in parallel structure:

“She is known for her beauty, intelligence, and being compassionate.”

The first two items — “beauty” and “intelligence” — are nouns. The last item is “being compassionate,” with “being” as a gerund (a verb that acts as a noun and ends with an “-ing”) and “intelligent” as an adjective. Therefore, “being intelligent” is not in the same form as “beauty” and “intelligence.”

Here’s the corrected version of the sample sentence:

“She is known for her beauty, intelligence, and compassion.”

All the items — “beauty,” “intelligence” and “compassion” — are nouns, and therefore they are in the same form. You can clearly see the parallelism in the structure of the sentence.

Transitional Words and Phrases

Transitional words are used to link words, sentences or phrases. They act as “guides” to help the reader to follow the flow of the discussion, enabling them to make sense between ideas. In ACT, transitions have three basic categories:

1) Addition (“also,” “moreover,” etc.) – to demonstrate an addition or continuation
2) Contrast (“however,” “still,” etc.) – to demonstrate conflicting ideas
3) Causation (“so,” “because”) – to demonstrate a causal relationship

Often, the correct use of punctuation marks will give you an idea the about the proper use of these transitional words and phrases.

Here’s an example of a sentence with the wrong use of transitional word and punctuation.

“I want to buy her a nice gift, however, I have to wait for my payday.”

The contrasting word there is “however.” But “however” and the comma after “gift” are the main problems of this sentence. There is a comma splice because the word “however” is sandwiched between two complete sentences (“I want to buy her a gift” and “I have to wait for my payday”). The comma after the word “gift” makes the comma splice.

We can correct this sentence by applying a proper punctuation or changing it a bit with another contrasting word
1) “I want to buy her a nice gift; however, I have to wait for my payday.” (The “however” acts as a conjunctive adverb that connects two independent clauses. The general rule in using “however” — with the same meaning as “nevertheless,” “yet” or “nonetheless” — is that it should be preceded by a semicolon and followed by a comma.)

2) “I want to buy her a nice gift, but I have to wait for my payday.” (The general rule in using “but” is that it should be preceded by a comma. However, use “but” only when you’re connecting two independent clauses that present contrasting ideas).

You should use these English grammar tips so that you can ace your scores in the English section and improve your ACT in Orinda scores overall. Studying these rules will also help you to compose well-constructed sentences in the Essay section in case your school or the college of your choice requires it.