Today's topic is "like" versus "as."
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.
A quick reminder about my audiobook, Grammar Girl's Quick and Dirty Tips to Clean Up Your Writing, a one-hour downloadable audiobook covering 24 different topics. You can buy the book for only $4.95 at iTunes and Audible.com.
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).