In continuation with the previous article Commonly Misused Terms and Phrases, we can see few more in this article.
Affect / Effect
You are not alone if you commonly confuse “affect” and “effect.” These two terms were confused in print as early as 1494. The key to correct usage here is to determine whether the term is being used as a noun or verb, and to discern the intended meaning.
“Affect” is usually used as a verb. (I think of the “a” in “affect” standing for “active verb.”) To “affect” is to “influence”:
The moon affects the tides.
“Effect” is usually used as a noun, and it means “outcome or result”:
Inflation is one of the effects of war.
Brackish water has negative effects on certain vegetation.
Finally—to the horror of many—“effect” can also be used as a verb to mean “to bring about,” as in the phrase “to effect a change,” while “affect” can be used as a noun (usually in psychology) to mean “conscious subjective emotion.” Such usages, though infrequent, highlight why you must be particularly careful to choose the correct term for the circumstances, keeping in mind both the intended meaning and the intended part of speech.
Alot / Allot
“Alot” is never correct. It is supposed to be two words—therefore: “a lot.” Never write a note to your composition professor at the end of the semester assuring her that you “really learned alot.”
“Allot” is to “assign a portion to”:
Twenty minutes were allotted to each speaker.
Alright / All right
All wrong. “Alright” is listed in most dictionaries as a common misspelling of what should be two words. In your writing, use “all right”:
Once you hear the high-pitched squeal of the recipient’s fax machine, it is all right to send your document.
Alternate / Alternative
As an adjective, “alternate” means “every other,” and it is usually used in relation to time or objects:
We were asked to focus on alternate lines of the figure. (Every other one.)
“Alternate” is also a verb, meaning “to switch back and forth in turns”:
The wet season alternates with the dry season.
“Alternative” denotes that a choice was made between at least two things:
He chose the polygon method as the best alternative for measuring compressible subsonic flow.