Rank ordering of 24 most frequently made errors according to the Cooper/Axelrod Study in 1995
1) wordiness [verbose]
2) misused word [usage]
3) incorrect or ambiguous pronoun reference [inc. pronoun] or [ambig. pronoun]
4) verb tense errors [tense shift]
5) missing comma between independent clauses [run on]
6) missing comma after introductory elements [no comma after intro]
7) problems with hyphens between compound adjectives [adj. hyp.]
8) capitalization errors [cap]
9) unnecessary comma between compound elements [comma in cmpd. not nec.]
10) incorrect spacing [sp]
11) missing words [missing]
12) missing comma with non-restrictive word groups [no comma non-rest.]
13) comma splice or fused sentence [fused]
14) problems in using quotation marks with other punctuation [quotes]
15) missing comma with transitional and parenthetical expressions and absolute phrases [no comma trans.] or [no comma abs.]
16) problems of pronoun-antecedent agreement [pron disagree]
17) incorrect preposition [inc. prep.]
18) misuse of who, which, or that [rel. pron]
19) unnecessarily complex sentence structure [KISS]
20) spelling out or using figures for numbers incorrectly [numb]
21) problems with apostrophes in possessive nouns [apost]
22) sentence fragment [frag]
23) missing comma in items in a series [no comma ser.]
24) unnecessary comma with restrictive word groups [comma in rest. not nec.]
Note: Abbreviations placed next to each type of error are for instructors who may use these abbreviations to indicate errors on student papers.