ACT® · English: Sentence Structure and Formation
Independent and Dependent Clauses
An independent clause has a subject and a working verb and can stand alone; a dependent clause has the same bones but a word like "because" or "although" bolted on front, so it must lean on another clause to finish the thought.
Every clause needs a subject and a verb that actually does something in that clause. 'The engine stalled' has both: engine is the subject, stalled is the verb, and the thought is finished. Nothing is missing. Add 'because' to the front and the grammar does not change at all, but the meaning does. 'Because the engine stalled' now promises a result that never arrives. You wait for the rest. That waiting is the whole test: can this group of words be read aloud, alone, as a complete and satisfying statement, or does it leave you hanging for a next part?
Words like because, although, since, while, and if are subordinators. Their job is to take a perfectly good independent clause and demote it, making it dependent on whatever comes next. To check any string of words, find the subject, find the verb that belongs to it, and then check the front of the clause for one of these leftover subordinators. If one is sitting there, the clause cannot stand alone no matter how complete it looks otherwise. In 'Although the rain stopped at noon, the field stayed too wet for the game,' the first half has a subject and verb but also 'although,' so it leans; the second half, 'the field stayed too wet for the game,' has no such word attached and can stand by itself. That is the independent clause.
This distinction is the foundation under every other rule in sentence structure and formation: run-ons happen when two independent clauses get jammed together without the right joint, and fragments happen when a dependent clause gets punctuated like it is independent. Once you can label clauses correctly, spotting those errors gets much faster.
Key terms
- Independent clause
- A clause with a subject and a working verb that expresses a complete thought on its own.
- Dependent clause
- A clause with a subject and verb that cannot stand alone because a subordinator makes it rely on another clause.
- Subordinator
- A word such as because, although, since, or while that attaches to a clause and makes it dependent.
- Fragment
- A word group punctuated as a sentence even though it is missing a subject, a working verb, or is left dependent.
- Working verb
- A verb form that is fully conjugated to show tense, as opposed to an -ing or -ed form standing alone without a helper.
Watch it explained
- How it worksHow does a word like 'because' or 'although' turn a complete thought into a piece that must lean on another?
- How it worksWalk me through testing any string of words for a subject and a working verb to see if it stands alone.
- Worked exampleFind the independent clause in 'Although the rain stopped at noon, the field stayed too wet for the game.'
- Common mistakeWhy isn't a long string of words automatically a complete sentence just because it is packed with nouns and verbs?
Check yourself
End of topic.