Khan Academy
Khan Academy: Run Ons and Comma Splices
A video [4:37] explaining the common sentence errors of run-ons and comma splices. L.11-12.3a Syntax
Sophia Learning
Sophia: Comma Splices and Run Ons
A screencast lesson defining comma splices and run-on sentences and explaining different ways to correct them. [3:16]
Khan Academy
Khan Academy: Dangling Modifiers
A modifying word or phrase 'dangles' when it doesn't apply to the word it's supposed to modify. Learn how to spot and fix this problem!
Khan Academy
Khan Academy: Run Ons and Comma Splices
A run-on sentence doesn't separate any of its independent clauses with the punctuation that it needs, and a comma splice incorrectly separates two independent clauses with a comma, instead of a comma-and-coordinating-conjunction.