Writing Style

One Space With Words

Use one space after a word unless it is followed by end punctuation. 

One Space With Punctuation Marks

Use one space after any punctuation mark at the end of a sentence.

Use one space after a comma, semi-colon, or colon within a sentence.

Use one space after punctuation marks within a reference list entry.

No Space for Abbreviations

i.e., etc. a.m. p.m.

Research participants initials: M.A.

One Space for Initials of Names

Author name in citation:  Ahmed, A. R.

One Space Within Mathematical Equations

Use one space between each item within mathematical equations.

a + b = c

a > b

More Information

See your APA manual, p. 154 (6.1 "Spacing After Punctuation Marks")

See your APA manual, pp. 187-188 (6.45 "Spacing, Alignment, and Punctuation for Statistics")