Because

I. Because answers the questions Why? and How?

Because is a subordinating conjunction; it is used to introduce a dependent clause (Allen; Lunsford). More particularly, because tends to introduce adverbial dependent clauses that answer the question why? When because answers the question why, it relates directly to the original statement, as in I came [why did you come?] because I wanted to see you (Allen).

Non-because adverbial clauses may answer questions like where? when? to what degree? and in what manner? Of course, these questions are not usually explicitly stated in the sentence. Dependent clauses that begin with that, which, who, and whom are not adverbial clauses (Siegel).

Because sometimes behaves a bit like the coordinating conjunction for (see Section IV-B). In this role, it may introduce a dependent clause by answering the question how? For example, I know he committed suicide,[how did you know that he committed suicide?] because his wife told me (Allen). Notice that you could probably swap a for for the because and still be fine.

II. Because at the beginning

Mrs. Harrison and your other junior high teachers were wrong. Prepositions fit fine at the end of sentences, because makes a swell first word (Allen; The American Heritage® Dictionary of the English Language, Fourth Edition), and there is one space after a period, not two. It’s also acceptable to use because after an introductory it’s, that’s, that is, etc: It’s because these socialist values are apparently being incorporated into the party doctrine that many fascists are changing their political allegiance (Allen). It’s not a great sentence, but it follows the rules.

By the way, the reason that Mrs. Harrison decried the use of because at the beginning of a sentence may have been that she wanted you to avoid separating a main clause and a subordinate clause into two separate sentences (e.g., I don’t want to go to work. Because I’d rather sleep) (Louisa). See the end of section IV.

Mrs. Harrison may have been thwarting the unholy communion of because and a noun clause (i.e., any clause or part of a sentence that stands in place of a noun(Bowles)). Grammarians argue that because should only introduce adverbial clauses (The American Heritage® Dictionary of the English Language, Fourth Edition), and naïve students may be tempted to write sentences like: Because the man is guilty (,) does not mean that he should be executed (Bowles), Because we don’t explicitly ask these questions doesn’t mean they aren’t answered (Allen), or Just because he thinks it a good idea doesn’t mean it’s a good idea (The American Heritage® Dictionary of the English Language, Fourth Edition). This form is fine for colloquial speech, but in addition to breaking some obscure rule of grammar, this kind of construction is impractical: it uncomfortably delays the main clause (Allen). Therefore, in formal writing do not use a clause beginning with because as the subject of the sentence (The American Heritage® Dictionary of the English Language, Fourth Edition).

III. Commas

Note the position of the commas in the section I examples. A comma should rarely be used when because answers the question why? It may be appropriate to precede a sentence-ending why?/because-clause with a comma if (a) the reason that follows the because is parenthetical (Siegel), (b) the writer is engineering an artificial or dialectical pause between the main statement and the reason, or (c) because is joined with of to form some kind of mutant prepositional phrase (this is probably wrong). I made those last two up. Here’s an example of a parenthetical (or prepositional phrase?) because: He’d have to watch his step…not to make a hash of things, because of over-anxiety. Notice that if you read the sentence aloud, it is natural to pause before “because of over-anxiety” (Allen), thus the comma.

Another instance when a comma may precede because is when it is used to answer the question how? For instance, in the last example of section I, the comma helps readers understand that because is not answering the question “Why did he commit suicide?”

And what about when because begins the sentence? There seems to be a nearly universal trend toward separating sentence-beginning adverbial clauses (especially ones that begin with because) from independent clauses with a comma (Rozakis; Siegel). However, occasionally you stumble across sentences like this: Because of the deterioration of the sugar in the blood it was decided, after consultation, to carry out an exchange blood transfusion (Allen). Notice there’s no comma. I suspect that the lack of a comma may be the author’s attempt to avoid a clunky comma party (Elisabetta).

Commas may also be necessary in sentences where the initial statement is negative. Please see Section VI for more information.

IV. Confusion with other words

A. Because versus As and Since

Because introduces a direct reason: I was sleeping because I was tired. (Notice that there’s no comma—it’s answering the question why?) In contrast, causal since (which has been a part of the English language since before Chaucer wrote in the fourteenth century) is useful as a slightly milder way of expressing causation than because. That is, since is appropriate when the first event in a sequence leads logically to the second event but was not its direct cause (Goldstein; The Chicago Manual of Style). The usage for as appears to be the same as since: As/Since I was tired, I was sleeping (The American Heritage® Dictionary of the English Language, Fourth Edition; Dictionary.Com Unabridged (V 1.0.1). Based on the Random House Unabridged Dictionary)—that is, it reads more like: Because I was tired, I happened to be sleeping.

As should be avoided when it could be construed to mean while.

Bad: She couldn’t answer her page as she was examining a critically ill patient.

Less bad: She couldn’t answer her page, as she was examining a critically ill patient.

Good: She couldn’t answer her page because she was examining a critically ill patient (Iverson et al.).

Since should be avoided when it could be construed to mean from the time of or from the time that (Goldstein; Iverson et al.; The Chicago Manual of Style; Publication Manual of the American Psychological Association).

Bad: She had not been able to answer her page since she was in the clinic.

Good: She had not been able to answer her page because she was in the clinic (Iverson et al.).

All three terms (because, as, and since) can be used at the beginning of a sentence. However, when these words are used to start a sentence, as/since tend to emphasize the main statement whereas because emphasizes the reason (Allen). See Section II.

B. Because versus For

Because and for may be interchangeable. However, it’s helpful to understand which attributes of because are the most amplified by for. In the sentence I know he committed suicide, for/because his wife told me, for/because answer the question How? (Allen). In this sentence, I was sleeping, for I was tired, for introduces the reason, proof, or justification like an afterthought or a parenthetical statement (Dictionary.Com Unabridged (V 1.0.1). Based on the Random House Unabridged Dictionary). (Notice that there’s a comma in both examples; for is a subordinate conjunction (i.e., for, or, so, nor, and, yet, but), so the comma preceding the reason is essential.

C. Because versus Inasmuch as

This phrase implies concession; the main statement is true in view of the circumstances introduced by this conjunction: Inasmuch as I was tired, it seemed best to sleep (Dictionary.Com Unabridged (V 1.0.1). Based on the Random House Unabridged Dictionary). Inasmuch as is a rather formal and awkward expression—avoid it! It means “to the extent that,” “in so far as,” or more simply, “in view of the fact that,” and “since.” The preferred style is two words, not four (Allen).

D. Because (of) versus Due to

Use due to when the main statement or effect is (1) stated as a noun and (2) appears before the verb be. Use because when the main statement or effect is stated as a phrase (Allen; The American Heritage® Dictionary of the English Language, Fourth Edition; Iverson et al.; Lunsford).

For example, due to is preferred in this sentence: His paranoia was due to the marshmallow candies that he was eating. The due to needs a noun or pronoun as its antecedent and, in this case, that noun is his paranoia. But because of is preferred in this sentence: The turtle-man was sweating profusely because of the shell on his back (Lunsford).

Other examples of due to:

Pay Caesar what is due to Caesar, and pay God what is due to God.

Incorrect speed is generally due to a word idler wheel.

It was due to start at four o’clock.

Part of her happiness, her unaltered sense of her own superiority, was due to…(Allen).

This can get confusing:

There was a delay due to bad weather – it’s an inverted version of The delay was due to bad weather, so it’s fine. However, if you change the sentence a bit more—The train was delayed due to bad weather—you’re in trouble. The due is no longer grammatically attached and is therefore unacceptable (Allen).

E. Because (of) versus Due to the fact that

Due to the fact that is long, confusing, and a grammatical mess. Therefore, always consider because (of) before using this awkward phrase.

That this slippage is so slight is due to the fact that because the other staff have worked a great deal of extra time.

*In cases where there is a strong link between due and an antecedent noun, due to the fact that may be preferred: The success of the tampon is partly due to the fact that it is hidden (Allen).

V. The reason is … because

Avoid this construction; it is redundant (The American Heritage® Dictionary of the English Language, Fourth Edition; Allen). The definition of because is “for the reason that” (The American Heritage® Dictionary of the English Language, Fourth Edition), so the sentence The reason for this was because I was the coolest man in the world literally means The reason for this was for the reason that I was really redundant (Allen). Another reason to avoid the reason/because construction is that because can only introduce adverbial clauses and that reason is requires completion by a noun clause (see last paragraph of Section II) (Bowles). Writers should also avoid the phrase the reason why. In both cases the sentences can easily be rewritten using that instead of because (The American Heritage® Dictionary of the English Language, Fourth Edition).

VI. Because and negatives

The last tricky characteristic of because is its use in negative sentences. For instance, what does this sentence mean: I do not eat chicken because of the feathers? Given the content of the sentence, we might assume that the speaker chooses not to eat chicken and that the reason he or she avoids chicken is because of poultry feathers. After all, who would want to eat feathers? However, without a comma between chicken and because, the sentence technically means something entirely different; the current sentence should technically be interpreted to mean I do eat chicken but I don’t eat it because of the feathers.

If it’s a negative statement with a valid reason for that negative statement, use a comma:

I do not eat chicken [negative statement], and the reason is the feathers [valid reason]

I do not eat chicken, because of the feathers. Notice the pause between chicken and because.

If it’s a positive statement with an invalid reason for that positive statement, don’t use a comma: I do not eat chicken [positive statement], but the reason that I eat it is not feathers [invalid reason]. I do not eat chicken because of the feathers. Notice that there’s no pause in this version; in fact, it almost sounds like there should be more to the sentence like I do not eat chicken because of the feathers, I eat it because of the tasty strips of beak.

Again, the context will often make the meaning clear (e.g., this sentence technically requires a comma but still meets Fowler’s approval even without a comma: Many people do not attend church because they are bored by ritualistic services), but a comma certainly helps oust ambiguity: The toy is not for every customer, because it does require some patience.

VII. Other subordinating conjunctions (see Lunsford)

VIII. Other compound prepositions (see Lunsford)

IX. References

Allen, Robert, ed. Pocket Fowler's Modern English Usage. Oxford: Oxford University Press, 1999.

The American Heritage® Dictionary of the English Language, Fourth Edition: Houghton Mifflin Company, 2004.

Bowles, Richard. "Don't Use "Because" To Start a Noun Clause". November 30, 2006 2006. <http://richardbowles.tripod.com/gmat/sc/sc_type6.htm>.

The Chicago Manual of Style. 15th ed. Chicago: University of Chicago Press, 2003.

Dictionary.Com Unabridged (V 1.0.1). Based on the Random House Unabridged Dictionary. Random House, Inc, 2006.

Elisabetta. "Beginning Sentences With "Because" ". Ed. Andrew David, 2006.

Goldstein, Norm, ed. The Associated Press Stylebook and Briefing on Media Law. Cambridge: Perseus Publishing, 2000.

Iverson, Cheryl, et al., eds. American Medical Association Manual of Style: A Guide for Authors and Editors. 9th ed. Philadelphia: Lippincott Williams & Wilkins, 1998.

Louisa. "Beginning Sentences With "Because"." Ed. Andrew David, 2006.

Lunsford, Andrewa A. The Everday Writer. Second ed. Boston: Bedford, 2001.

Publication Manual of the American Psychological Association. 5th ed. Washington, DC: American Psychological Association, 2001.

Rozakis, Laurie E. The Complete Idiot's Guide to Grammar and Style Penguin Group, 2003.

Siegel, Kevin A. "Writing: Commas, Commas, Commas." I Came, I Saw, I Learned... IconLogic, 2006. Vol. 2006.