The root of this “like versus as” controversy is that traditionally like is a preposition and as is a conjunction. Nevertheless, people have been using like as if it were a conjunction (as I did) for at least 100 years, and grammarians have been raging against that use for just as long. In fact, the Harper Dictionary of Contemporary Usage states that “probably no single question of usage has created greater controversy in recent years” than the conjunctive use of like.
In 1954, an advertising campaign for Winston cigarettes brought the debate into the public eye. Winston said their cigarettes tasted good “like a cigarette should,” and language lovers were outraged because the ad should have said, their cigarettes tasted good “as a cigarette should.”
What Are Prepositions and Conjunctions?
Let’s quickly review what a preposition is, and what a conjunction is. According to the book Woe Is I, a preposition is “a word that ‘positions’ or situates words in relation to one another.” Examples are in, around, and through. A conjunction is, simply, “a connecting word.” Common conjunctions are and, but, and or (1).
When to Use Like, When to Use As
The proper way to differentiate between like and as is to use like when no verb follows (2). For example, Squiggly throws like a raccoon or Aardvark acted just like my brother. Notice that when I use like, the words that come after are generally simple. A raccoon and my brother are the objects of the preposition.
If the clause that comes next includes a verb, then you should use as. For example, Squiggly throws as if he were a raccoon or Aardvark acted just as I would expect my brother to behave. Notice that when I use as, the words that come after tend to be more complex.
You generally hear like used in everyday speech, so that helps me remember that like is the simpler word—or at least it is followed by simpler words. As sounds stuffier and is followed by a more complex clause that contains a verb.
The Like Versus As Controversy
Whether you abide by this rule or not probably depends on how much of a grammar stickler you are. It's common to hear sentences like this: It's like I'm looking at my twin. And as a result, many people don't know it's wrong. In one survey, 21 percent of professional writers and editors said they found such constructions acceptable in casual speech. On the other hand, only 6 percent thought the construction would be OK in formal writing (3).
I have to admit that after reading entries in four usage guides (3,4,5,6), I felt a bit brow beaten about the whole topic. Even as like is becoming more entrenched in everyday use, professional grammarians are absolutely resolved that this is a trend worth fighting. Many language experts seem fully prepared to rail against it with all their might, and some of the comments were quite vicious.
So my advice is don't do it—don't use like as a conjunction, especially in writing, unless you are ready for the full force of rampaging grammarians to rain down on you (which is not what I'm generally going for in the advice I give you).
Here are more examples of correct sentences to help you remember the rule:
My cousin looks like Batman.
My neighbor yelled like a banshee.
It's as if my cousin thinks he is Batman.
My neighbor yelled as though he had seen a banshee.
As if Versus As Though
A final note is that there is no discernible difference between as if and as though. Some sources say that as if is often used for less likely scenarios—my cousin being Batman—and as though for more likely scenarios—my neighbor is a maniac—but this isn't a definitive rule.
- O'Connor, P. Woe Is I: The Grammarphobes Guide to Better English in Plain English. New York: Riverhead Books, 2003.
- Lynch, J. The Guide to Grammar and Style. andromeda.rutgers.edu/~jlynch/Writing/l.html (accessed April 9, 2007).
- Morris, W. and Morris, M. Harper Dictionary of Contemporary Usage. Second edition. New York: Harper & Rowe, 1985, p. 52.
- Burchfield, R. W, ed. The New Fowler's Modern English Usage. Third edition. New York: Oxford, 1996, p. 458.
- Garner, B.A. Garner's Modern American Usage. Oxford: Oxford University Press, 2003, p. 496.
- "Use and misuse of 'like.'" The Chicago Manual of Style Online, 16th edition. Section 5.181. The University of Chicago Press. http://www.chicagomanualofstyle.org/16/ch05/ch05_sec181.html?para= (accessed September 2, 2013).
(Please retain the reference in reprint: http://www.letpub.com/index.php?page=author_education_evidence)