4 Rules of English Grammar You Don’t Realize You Already Know

English grammar can be tricky. If you grew up in an English-speaking country, you may remember diagramming sentences in school, agonizing over past participles and adverbial clauses. However, chances are that your grammar classes only went over a teeny tiny proportion of the rules that govern English.
Does that scare you? It shouldn’t. If you’re a native speaker (or otherwise extremely fluent), you likely know them so well that you’ve never even thought of them as rules. Still, you’ll know intuitively that these four sentences are wrong:

Examples

1. My friend got riding leather brown new nice boots.

Why does it sound wrong? Maybe you never consciously realized that there are rules governing adjective order, but you do follow them. Wouldn’t you know to say “My friend got nice new brown leather riding boots,” automatically?

English adjectives are generally arranged such that the adjectives describing the properties most essential to the item appear closest to the noun. The most common order is this: number, opinion, size, age, shape, color, origin, material, purpose. There are exceptions, mostly related to either shades of meaning or to the sounds of the adjectives themselves – but again, you already have a subconscious grasp of that.

2. My friend doesn’t think that’s a good idea, but I think it’s.

Why does it sound wrong? Most of the time, shortening is or are will work perfectly well at the start or in the middle of a sentence (“that’s a good idea” sounds fine above). But putting it at the end makes it sound like something’s missing – if you changed the “it’s” above to “it is,” everything would be fine.

There are rules that govern when you can and can’t contract these forms of to be. (Incidentally, if you speak African-American Vernacular English, the same rules govern when you can drop forms of to be.)

3. The assignment was confusing, so the teacher broke down it into smaller pieces.

Why does it sound wrong? In English grammar, you can pretty much always substitute a pronoun for a noun (“The boy ate the apple” and “He ate it” both sound fine, grammatically). The one exception is certain phrasal verbs.
Go over can mean review, call off can mean cancel, and pick on can mean mock. These are examples of phrasal verbs, idiomatic phrases that combine a verb with one or more other words to yield a new meaning. They work weirdly. You can call the meeting off or call off the meeting. While you can pick on your classmate, though, you can’t pick your classmate on. When using nouns, there are some phrasal verbs (like call off) that can be split up, and others (like pick on) that can’t.

Pronouns, though, you can only put at the end of the phrasal verb. You can call it off, but not call off it. And even without knowing the rule, you know you want to change the sentence above to say “the teacher broke it down into smaller pieces.”

4. Melvin dined the pizza.

Why Does It Sound Wrong? This sentence – borrowed from Steven Pinker’s The Language Instinct – is easy to understand. Still, no native speaker would naturally say it.

In his book, Pinker argues that this is because your mental definition of dine is linked to someone doing the eating, but not to something being eaten. In any case, some verbs, like dine, refuse direct objects. Others, like eat, can go either way (“Melvin ate the pizza” and “Melvin ate” both sound fine). Still others actually require an object (“Melvin devoured” just sounds incomplete).

Conclusion

The craziest part of all this is that, if you’re a native speaker, you figured out which verbs went in which category before you turned seven.

Yes, English grammar is complicated, but if English is your mother tongue, you’ve known most of the rules since you were a very young child. So what was with all those “no split infinitive”-type rules you had to learn in school? Aren’t those the real rules of English grammar?
Well, it depends on your outlook, but here’s a little secret: most of the rules you learned in grammar class are probably not as set-in-stone as you think. In fact, conceptions of “proper English” have evolved over time, as has the English language itself.