Language: Mechanics, Usage, and Expression
The skill map
Language items split into mechanics (capitalization, punctuation) and expression (usage, sentence structure, paragraph organization). Know these clusters: end marks; commas in a series, in dates, and after introductory phrases; apostrophes for possession and contractions; quotation marks around dialogue; subject–verb agreement, including across interrupting phrases; pronoun case and clear pronoun reference; consistent verb tense; adjective versus adverb; correct comparative and superlative forms; avoiding double negatives; and sentence completeness - no fragments, no run-ons, no comma splices.
Traps worth naming
- Over-punctuation. Test writers supply commas that should not be there. Never place a single comma between a subject and its verb.
- Apostrophe confusion. Its is possessive; it's means "it is." Plain plurals take no apostrophe (three dogs); possessives do (the dogs' bowls).
- The interrupting phrase. In "The box of old letters ___ in the attic," the verb agrees with box, not letters.
- Ambiguous pronouns. If he could refer to either of two people, the sentence needs a noun instead.
- "Sounds fine" choices. A phrasing that is natural in speech may repeat a subject or shift tense; check the whole sentence.
Rule of thumb
Find the independent clauses first. Two complete sentences need a period, a semicolon, or a comma plus a coordinating conjunction - never a bare comma.
Worked example
"The team, after weeks of practice, ___ ready." The subject is team, a collective noun treated as one unit, so the verb is was. The commas are correct because they set off an interrupting phrase in the middle of the sentence; the phrase does not change the subject.