Revelle Humanities Grammar Handbook
6 Sentence fragments
7 Run-on sentences
8 Verb agreement
13 Passive voice
15 ESL
17 Misplaced modifiers
18 Pronoun reference
20a Comparisons
21 Parallel construction
23 Commas
23d Sexist language
25/6 Semicolons & colons
29 Ellipsis
31 Brackets
35 Apostrophes
36 Abbreviations
37 Underlining
39 Numbers
41b Slang
41e Jargon
41f Pretentious language
42c Idioms
42e Clichés
43a Fluff

18 Pronoun reference
Unclear pronoun references often lead to great confusion among readers. Generally, be sure your pronoun references are specific.

Unclear pronoun references: It is well-known that The Odyssey teaches you the principles of hospitality and generosity. This is clear in the episode of the Cyclopes.

Revised: The Odyssey teaches the principles of hospitality and generosity. Hospitality is clear in the episode of the Cyclopes.