A lot or Alot?

A lot should be written as two words. Although a lot is used informally to mean "a large number" or "many," avoid using a lotin formal writing. Example: The crook had many [not a lot of] chances to rob the stranger.

A or An?

"Use a before a consonant sound; use an before a vowel sound. Before a letter or an acronym or before numerals, choose aor an according to the way the letter or numeral is pronounced: an FDA directive, a U.N. resolution, a $5.00 bill" (Merriam-Webster's Dictionary of English Usage). Please note: This is the basic rule. For a more thorough presentation of the complexities of using a or an, see the source cited here.

Accept or Except?

Accept is a verb meaning "to receive" or "to approve." 
Example: "I accept your offer of the book." 
Except is a preposition meaning "excluding" or "leaving out." 
Example: "He liked everything on the plate except the liver." 
Except can also be a verb meaning "to leave out" or "to exclude." 
Example: "He excepted all Corvettes from his list of favorite cars."

Acronyms and Initialisms?

"Acronyms are formed by combining the first letter or letters of several words; they are pronounced as words and written without periods" (Alred, Brusaw, and Oliu, The Business Writer's Handbook). Examples: radar (radio detecting and ranging), COBOL (Common Business-Oriented Language), scuba (self-contained underwater breathing apparatus). "Initialisms are formed by combining the initial letter of each word in a multiword term; they are pronounced as separate letters" (Alred, Brusaw, and Oliu). Examples: e.o.m. (end of month), c.o.d. (cash on delivery), p.m. (post meridian). Usage guidelines:

• "Except for commonly used abbreviations (U.S., a.m.), spell out a term to be abbreviated the first time it is used, followed by the abbreviation in parentheses. Thereafter, the abbreviation may be used alone.
• In long documents, repeat the full term in parentheses after the abbreviation at regular intervals to remind readers of the abbreviation's meaning, as in "Remember to submit the CAR (Capital Appropriations Request) by. . . ."
• Do not add an additional period at the end of a sentence that ends with an abbreviation (example: The official name of the company is DataBase, Inc.).
• Write acronyms in capital letters without periods. The only exceptions are acronyms that have become accepted as common nouns, which are written in lowercase letters, such as scuba (self-contained underwater breathingapparatus).
• Generally, use periods for lowercase initialisms (a.k.a., e.d.p., p.m.) but not for uppercase ones (GDP, IRA, UFO). Exceptions include geographic names (U.S., U.K., E.U.) and formal expressions of academic degrees (B.A., M.B.A., Ph.D.).
• Form the plural of an acronym or initialism by adding a lowercase s. Do not use an apostrophe (CARs, DVDs).

Do not follow an abbreviation with a word that repeats the final term in the abbreviation (ATM location not ATM machine location)" (Alred, Brusaw, and Oliu).

Active or Passive Verbs?

"The voice of a verb indicates the strength of the subject in a sentence. It tells us whether that subject takes action or receives action. There are two possible voices: active and passive. In the active voice, the stronger form, the subject of the sentence takes the action of the verb.
     Our army won the battle.
The subject army is strong since it takes action. This sentence uses the active voice. In the passive voice, the weaker form, the subject is acted upon. 
     The battle was won by our army.
In this sentence, the subject battle is weak because it receives the action of the army. It takes no action of its own —a battle cannot win itself — and so the sentence uses the passive voice" (Strumpf and Douglas, The Grammar Bible 38).