Use instructor instead for postsecondary purposes.
that and which
Use that to introduce a restrictive clause, which to introduce a nonrestrictive clause. How to choose? Consider whether the meaning of the sentence would be changed if the clause were removed.
Restrictive: Steinbeck wrote the book that made me want to move out west.Nonrestrictive: The Scarlett Letter, which I read in high school, has been made into a movie.
Use a comma or pair of commas to set off a nonrestrictive clause: Of Mice and Men, which is banned in many school districts, is considered an American classic.
If that appears earlier in the sentence, it is acceptable to use which in place of that to introduce a restrictive clause–but use no comma.
Is that the Steinbeck book which made you want to move out west?
that and who
Use that for objects, who for people.
Incorrect: He is the man that married my sister.Correct: He is the man who married my sister.
Use figures except for noon and midnight. Never write 12 noon or 12 midnight–this is redundant. Only use a colon when separating hours from minutes: 3 p.m., 7:30 a.m. Omit :00 when listing times. Always include a.m. or p.m. with the time. Avoid using o'clock when referring to time.
7 a.m.–4 p.m.; 7–9 p.m.; 7:30 a.m.–9 p.m., 9:20 a.m.–12 p.m. (use an endash between times and not a hyphen)
Articles, press releases, promotional materials and the like—it is only necessary to use a trademark symbol with the first instance of the mark, or with the most prominent placement of the mark.
tune-up (n.), tune up (v)
The car needs a tune-up; the shop will tune up the engine.