A simple sentence has one independent clause, and a compound sentence has two or more. A complex sentence adds a dependent clause, and a compound-complex sentence has both. A comma splice joins two independent clauses with only a comma. Fix it with a period, a semicolon, a comma plus FANBOYS, or a subordinator.
What are the four sentence types?
Simple: One independent clause. It may have a compound subject or verb and extra phrases, but only one subject-verb core.
Compound: Two or more independent clauses, joined by a comma plus a coordinating conjunction (FANBOYS) or by a semicolon.
Complex: One independent clause plus at least one dependent clause, which starts with a subordinator (because, when, although) or a relative pronoun (who, which, that).
Compound-complex: Two or more independent clauses plus at least one dependent clause.
How do you fix a comma splice or run-on?
Period: make two sentences.
Semicolon: join two closely related independent clauses.
Semicolon plus a transition word and a comma: "; however," or "; therefore,".
Comma plus a coordinating conjunction (for, and, nor, but, or, yet, so) that fits the meaning.
A subordinator such as because, although or after, which turns one clause into a dependent clause.
Not a fix: a comma alone, or a comma before "however".
How the lab works
Part 1: classify nine original sentences by type.
Part 2: repair six run-ons and comma splices; the lab shows the sentence you build and accepts every repair that is grammatical and keeps the meaning.
Part 3: put the sentences of two short paragraphs in order, as in an ordered-response question.
Practice mode gives feedback on each item; exam style scores each set all-or-nothing.
What is the difference between a comma splice and a run-on?
Both join two independent clauses incorrectly. A comma splice uses only a comma between them. A run-on, or fused sentence, uses no punctuation at all. The same four repairs fix both.
Can I fix a comma splice with "however"?
Only with a semicolon. "However" is a transition word, not a conjunction, so "The clinic was busy, however the wait was short" is still a comma splice. Write "The clinic was busy; however, the wait was short."
What are FANBOYS?
FANBOYS is a memory aid for the seven coordinating conjunctions: for, and, nor, but, or, yet and so. A comma plus one of them can join two independent clauses into a compound sentence.
How do I tell a complex sentence from a compound sentence?
Count the clauses that could stand alone. A compound sentence has two or more independent clauses. A complex sentence has one independent clause plus a dependent clause that starts with a word such as because, when, although, who or which.
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