Grammar: parallel structure, phrases, clauses, and punctuation (grade 9) · lesson

Parallel structure

💡 Items in a list or a pair should share the same grammar form, like all -ing words or all adjectives.

Parallel structure means matching forms. "I like reading, cooking, and gardening" matches: three -ing words. "I like reading, to cook, and gardens" does not.

To fix a list, find the form most items use, then make the odd one match. If two items are adjectives, like "quick" and "cheap," the third should be one too, like "reliable."

Paired words work the same way: either/or, neither/nor, both/and, and not only/but also. What follows the first half should match what follows the second.

🧠 Let's work it out

Check "She wants to travel, learning Spanish, and to cook."

Two items start with "to," and one is an -ing word.
Change it to "to travel, to learn Spanish, and to cook."
For pairs, put a finger on the word after "either" and the word after "or."
Same kind of word? Then it's parallel.

What do you think comes next?

parallel structure: using the same grammar form for items in a list or pair

Joining sentences: semicolons, commas, and run-ons

💡 Join two complete sentences with a semicolon, or with a comma plus a word like "and" or "but"; a comma alone makes a comma splice.

An independent clause can stand alone as a sentence. To join two of them, use a semicolon, or a comma with "and," "but," "or," or "so." A comma by itself makes a comma splice. No mark at all makes a run-on.

Check a semicolon by covering it: both sides must be full sentences. A dependent clause, one that starts with a word like "because" or "when," can't sit on either side.

Words like "however," "then," and "therefore" are not joining words. When one starts the second sentence, put a semicolon before it. Put a comma after "however" or "therefore."

🧠 Let's work it out

Fix "The bus was late, we walked to school."

Both halves are full sentences, so the comma alone is a splice.
One fix: "The bus was late; we walked to school."
Another: "The bus was late, so we walked to school."
With "therefore": "The bus was late; therefore, we walked to school."

What do you think comes next?

independent clause: a group of words that can stand alone as a sentence
comma splice: two sentences joined by only a comma
run-on: two sentences joined with no punctuation

Clauses and subordinating conjunctions

💡 A subordinating conjunction like "when," "because," or "although" turns a clause into one that can't stand alone.

A clause has a subject and a verb. An independent clause stands alone. A dependent clause can't, because it starts with a subordinating conjunction such as "when," "because," "although," "if," "since," "after," or "until."

When a dependent clause comes first, put a comma after it: "Because it snowed, school closed."

To find the subordinating conjunction, find the clause that can't stand alone. Its first word is usually the one.

🧠 Let's work it out

In "After the movie ended, we walked home," which part can't stand alone?

"After the movie ended" leaves you waiting for more.
Its first word, "after," is the subordinating conjunction.

What do you think comes next?

dependent clause: a clause that can't stand alone as a sentence
subordinating conjunction: a word like when, because, or although that starts a dependent clause

🔗 Khan Academy: Grammar: sentences, clauses, and phrases (grade 9) · Khan Academy (free) ↗

Verbals and the phrases they start

💡 A verbal is a verb form doing another job: a gerund acts as a noun, a participle describes, and an infinitive often names a purpose.

A gerund is an -ing verb used as a noun: "Running clears my head." Ask what the sentence is about. Not every -ing word is a gerund. "Evening" and "ceiling" are plain nouns.

A participle is a verb form used to describe, like "broken" or "smiling." A participial phrase, such as "Tired from practice," describes a noun, usually the one right after the comma.

An infinitive is "to" plus a verb, like "to win." An infinitive phrase often tells why: "She practiced to win the contest."

If the word after an opening phrase isn't the one doing the action, the phrase dangles. "Reaching for the jar, the shelf tipped over" says the shelf reached.

🧠 Let's work it out

Look at "Shaking with cold, the hikers built a fire."

Who is shaking? The hikers, and they come right after the comma, so it's correct.
"Shaking" is a participle describing them.
In "Climbing is fun," "climbing" names an activity, so it's a gerund.

What do you think comes next?

gerund: an -ing verb used as a noun
participle: a verb form used to describe a noun
infinitive: to plus a verb
dangling modifier: a describing phrase with nothing sensible to describe

Colons

💡 A colon comes after a complete sentence and points to what follows, like a list or an explanation.

The words before a colon must make a complete sentence. Then the colon introduces a list, a single word, or a rule: "She had one goal: finish."

Never put a colon right after a verb or a preposition. "My pets are: a cat and a dog" is wrong. Drop the colon, or write "I have two pets: a cat and a dog."

🧠 Let's work it out

Test "We need: eggs, milk, and bread."

Cover everything after the colon.
"We need" isn't a full thought, so the colon is wrong.
Fix it: "We need a few groceries: eggs, milk, and bread."

What do you think comes next?

Commas around extra information

💡 Set off information with commas only if the sentence would still tell you who or what without it.

An appositive is a noun phrase that renames another noun: "Mr. Lee, our coach, blew the whistle." Extra information like this needs a comma on both sides.

Clauses that start with "who" or "which" follow the same rule. If the clause is needed to tell which one you mean, use no commas. If it's just extra, use commas on both sides.

Ask: if I remove it, do I still know who or what? Earth has one moon, so in "The moon, which was full, lit the path," the clause is extra.

🧠 Let's work it out

Compare "The students who finished early went to lunch" with "The students, who finished early, went to lunch."

The first means only the early ones went.
The second means all the students went, and all of them happened to finish early.
The commas change the meaning.

What do you think comes next?

appositive: a noun phrase that renames the noun beside it
nonessential: extra, not needed to tell which one