Whether a noun can be counted determines its article, its plural, and which of much, many, few and little you can use with it.

Most of the world’s languages manage without articles. English uses them constantly, and the rule is not about grammar — it is about what the listener already knows.

The same seven words carry seven meanings depending on where one of them sits. Most misplaced modifiers are invisible until someone reads them literally.

Fast, hard, late and straight are adverbs with no -ly at all. Friendly, lonely and lively are adjectives that look like adverbs. The ending proves nothing.

“I’m good” is not an error. “She sings good” is. The line between them is the same one that decides “I feel bad”.

Every one of these is a correctly spelled word, so nothing will flag it. The only defence is knowing the trick for each.

One takes an object and one does not, which would be simple except that the past tense of “lie” is “lay”. English did this on purpose to no one.

One means repeatedly, the other means without stopping. A handful of near-identical pairs carry real distinctions, and a handful carry none at all.

The whole comprises the parts. The parts compose the whole. And “is comprised of” is the construction that starts arguments.

The speaker implies. The listener infers. Confusing them is common enough that some dictionaries now record the error, which does not make it a good idea.