Prose where every sentence runs the same length reads as flat, however correct it is. Variation is the fix, and it is almost mechanical.

English rearranges the sentence to ask a question, and then inserts a helper verb that was not there before. Few languages make you do both.

Who, which, that, whose and where let you attach a whole clause to a noun. The comma decides whether the information is essential.

Three tiny words governing when and where, with a pattern underneath that most textbooks never state.

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.