usage

Contractions aren't bad in everyday writing, but they are not acceptable in scientific writing.

Between is used when there are two items; among is used when there are more. I traveled between Chicago and Cincinnati, but I traveled among Chicago, Cincinnati, and Cleveland.

A debate may "center on" a certain issue, but it cannot "center around" it. The phrase "centers on" is a geometric reference. A circle centers on a single point. Imagine…

When using quotation marks, always start with double and then alternate with single. "But," you will say, "my math teacher told me, 'One comes before two.'"

When writing phrases that are side remarks to the main point of a sentence, always start with parentheses first and then alternate with brackets (in general [in math, sometimes brackets…

Diseases are named after their discoverers, but there is not a possessive. Alzheimer disease was discovered by Alzheimer, not suffered by him. So it is not Alzheimer's disease. Lou Gehrig…

People are "aged" a certain time. Someone is aged 21. Or you study happiness in children aged 8-10. Not "ages."

Math symbols get a space on either side. Math symbols are words. "=" equals the word equals. Thus, as if the whole word were there, a space would be on…

Similar to the previous entry: "since" refers to time. I have been up since seven this morning. If you want to start a sentence with a phrase that justifies what…

I recommend that you use the word "because" instead of the word "as" in phrases suggesting causality, such as "this will make us rich as it involves winning the lottery."…