Editorial Tip: Like vs. As

One of the more enduring grammar debates concerns the use of like versus as. The primary discrepancy is whether or not common usage of like, traditionally a preposition, also establishes its use as a conjunction in place of as.

A preposition joins nouns, pronouns and other words within a sentence: "This meat tastes like chicken." Notice that the preposition like introduces the noun chicken. A conjunction connects words, phrases and clauses: "Suddenly, I felt as if I was not alone." As if is the conjunction that joins the first clause, Suddenly, I felt with a second, I was not alone and is followed by the verb was. Enter the discrepancy: "Suddenly, I felt like I was not alone." This may sound correct to the average ear or in an informal conversation but following the preposition with a verb does break with grammar rules.

Several sources allow for the popular usage, citing centuries of common speech. Strunk and White firmly maintains that like is not an acceptable substitution, arguing: "If every word or device that achieved currency were immediately authenticated, simply on the ground of popularity, the language would be as chaotic as a ball game with no foul lines." Wherever one may fall along the spectrum regarding the increasingly relaxed use of like—as an inevitable evolution or a corruption of the English language—there remains a basic principle regarding the use of like versus as:

The preposition like compares unlike things and is followed by nouns and pronouns.
The conjunction as compares similar things and is followed by verbs.

Likely, the informal use of like as a conjunction will not garner a correction and there are several instances where common usage does override the use of as. Still, for the formal essay or text, defaulting to the proper usage will yield the most accurate language.

For additional examples, opinions and explanations see the Chicago Manual of Style, The Copyediting Handbook, and Bartleby.com: http://www.bartleby.com/64/C001/033.html and http://www.bartleby.com/64/C001/012.html.