Clauses and the Comma Splice
A 45-minute grammar lesson that treats the comma splice as a clause problem rather than a punctuation rule: find the independent clauses first, then choose among the four ways to join them.
Grammar
Subject
Grades 6-8
Grade Level
45 minutes
Duration
Clauses
Topic
On this page: Materials · Warm-Up · Direct Instruction · Guided Practice · Independent Practice · Assessment · Closure · Related Resources
Learning Objectives
By the end of this lesson, students will be able to:
- Identify the subject and verb in a clause
- Tell an independent clause from a dependent one using the stand-alone test
- Explain why a comma alone cannot join two independent clauses
- Fix a comma splice in four different ways
- Choose a join that fits the relationship between the two ideas
Materials
- Independent and Dependent Clauses Worksheet — one copy per student
- Comma Splices Worksheet — one copy per student
- Compound-Complex Sentences Worksheet, for extension
- Strips of card with one clause written on each, enough for pairs to build sentences
- The four fixes written on the board and left up all lesson
Vocabulary
- Clause — a group of words with a subject and a verb
- Independent clause — a clause that could stand alone as a sentence
- Dependent clause — a clause with a subject and verb that cannot stand alone
- Subordinating conjunction — a word like because, although, when, or if that makes a clause dependent
- Coordinating conjunction — and, but, or, nor, for, so, yet
- Comma splice — two independent clauses joined by a comma with no conjunction
Preparation
Write the four fixes on the board before class and leave them up: a period, a semicolon, a comma plus a coordinating conjunction, or make one clause dependent. Students will refer to them constantly and the list stops the lesson becoming a memory test.
Cut clause strips — roughly two-thirds independent, one-third dependent, all on the same subject so any two can be combined into something that means something. Mixed topics produce nonsense pairings and the nonsense distracts from the grammar.
Pull two or three real comma splices from student writing if you can, with names removed. A splice from the class’s own work does more than an invented one, because nobody can dismiss it as a textbook sentence nobody would write.
Warm-Up
5 minutes. Put two sentences on the board, identical except for the punctuation at the join: one a clean splice, one correctly joined. Ask which is correct.
The class will split, and the arguments will be about the comma — it looks fine, it sounds fine, there is a pause there. Let that run for a moment, because every one of those reasons is about the comma and none of them is about the sentence.
Then say where the lesson is going: the comma is not what decides this. What decides it is what sits on either side of it, and by the end of the lesson they will be able to check that in about two seconds.
Direct Instruction
12 minutes. Start with the clause, not the error. A clause is a subject and a verb. Put four on the board and have the class find both in each one, quickly, without discussion — this part should feel easy.
Then introduce the test that the whole lesson runs on: cover everything else and ask whether what is left could be a sentence on its own. If yes, it is independent. If no, it is dependent. Do it out loud with your hand physically covering the rest of the sentence, because students copy the gesture and the gesture is the skill.
Now show what makes a clause dependent. Take an independent clause — the bus was late — and put because in front of it. Nothing else changed. It still has a subject and a verb, and it can no longer stand alone. Say that plainly: one word did that, and there is a short list of words that do it.
Only now name the error. Two independent clauses joined by a comma alone is a comma splice, and it is the one join that is not available. Point at your warm-up sentence and run the test on each side, and the disagreement resolves itself.
Put up the four fixes and apply all four to the same splice, one after another, reading each aloud. Then ask the question that makes this a writing lesson rather than a proofreading one: which of these four is best here, and why? A period makes two separate facts. A semicolon says these two belong together. But says they pull against each other. Because says one caused the other. The class is choosing meaning, not correctness.
Guided Practice
13 minutes. Pairs get the clause strips. First job: sort them into independent and dependent using the covering test, with the hand gesture. Fast, and it should be fast.
Second job: build three sentences from the strips, one for each of these —
- two independent clauses, correctly joined
- one independent and one dependent clause
- a deliberate comma splice, then fixed two different ways
Making a splice on purpose is worth more than finding ten. A student who has to construct one has to know what the parts are, and after that the error is never mysterious again.
Circulate and ask one question: cover it — can that stand alone? Do not answer whether a sentence is right; make them run the test in front of you. The point of this block is that the test becomes automatic, and it only becomes automatic by being used aloud more times than feels necessary.
Pairs then start the Independent and Dependent Clauses Worksheet together.
Independent Practice
10 minutes. Students finish the clauses worksheet, then work the Comma Splices Worksheet alone.
Add one requirement to the splice page: for two of the fixes, write a sentence saying why that fix and not another. That single line is what turns the exercise from proofreading into a decision, and it is the part that shows up later in their own writing.
Assessment
3 minutes. Exit ticket, three items. Underline the independent clause in a given sentence. Is this sentence a comma splice, yes or no? Then: fix this splice two different ways, and say which you prefer.
The third item is the one that discriminates. Fixing a splice one way can be done from memory of the last example; fixing it two ways and defending a choice cannot, and the defense is where you see whether the four joins mean anything to the student or are just a list.
Closure
2 minutes. Go back to the warm-up pair and ask the class to settle it now. Someone will run the test out loud, which is the outcome. Close on the sentence the lesson earns: the comma was never the question — find the clauses first, and the punctuation tells you what it needs.
Differentiation and Accommodations
- Extra support: stay with the sorting and drop the splice for today. Telling an independent clause from a dependent one is the whole foundation, and the independent and dependent clauses worksheet is a full page of exactly that, free with a member account.
- Extension: compound-complex sentences is the natural next step for students who sorted quickly — two independent clauses and a dependent one in the same sentence, which is where the four joins start doing real work.
- Common difficulty: a student who marks every long clause independent and every short one dependent. Length has nothing to do with it. Give them a very short independent clause (she left) and a long dependent one, and the rule of thumb collapses on its own.
- Watch for: the sentence joined with however or therefore and a comma. Students read those as conjunctions because they behave like them in meaning, but they do not join clauses, and the result is a splice that looks more educated than the usual kind. It is worth naming out loud once.
Extension Activities
Phrases and clauses is the useful companion page: a phrase has no subject-verb pair at all, and students who can separate the two stop mistaking a long phrase for a clause.
Complex sentences takes the dependent clause and puts it to work deliberately, which is the writing payoff of everything taught here.
Run a splice hunt in the class’s own drafts for the rest of the term. Students find their own far more readily once they have built one on purpose, and a splice found in your own paragraph is worth twenty found in an exercise.
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