Fill in the blank with the correct form of sneak. Don't think too much about the question, just write your natural response:
Everyone in the house was sleeping, so he _________ across the yard. [sneak]
Some of you (or most of you, considering how much of this blog's readership comes from people I know personally) may have gotten this brief survey in their e-mail last week. The issue came up in my advanced junior high school class when we were reading about a nature photographer who snuck up on a baby lion to get the perfect photograph. The wording was a source of confusion for one student, who checked her dictionary to find that "sneaked" or "snuck" were both acceptable, the former listed as "more formal." This sounded wrong to me, for I, as a native speaker of English, would never use "sneaked," and told the class as much.
The matter bothered me, so I did what most eikaiwa teachers would never do: I looked it up. (Or did a quick Google search, if you want to get technical.) A majority of what I found seemed to agree that while "sneaked" was the original past form of "sneak," "snuck" had more recently become acceptable (though some people, like Jennifer Garner below, strongly argued the contrary).
I was curious to see if more people agreed with Jennifer Garner or me, so I sent out the survey. Roughly 80% chose "snuck" as their past tense form of choice, some strongly, and some through great deliberation. (A few did the same Google search I did, or discussed varying situations in which they would use "snuck" or "sneaked," and I did not count these in the final results.) My trusty Random House dictionary says that, "SNUCK has occasionally been considered nonstandard, but is now so common that it can no longer be so regarded."
Students come to me to learn common English for social situations and practical use. They want to express themselves, understand what they read, and speak natural English that will not cause them shame or embarrassment. I would never correct a student who used a past form of "sneak" that I didn't agree with, just as I would never correct a student who used "hopefully" to refer to a future wish, or who used "their" as a gender neutral possessive pronoun. These are mistakes that millions of native English speakers make every day, and that all but the strictest of grammar critics would brush aside in natural conversation. Occasionally I have students whose English is good enough to understand and appreciate such finer subtleties, but for the rest there's no point in correcting errors that don't sound brutally jarring to the average gaijin.