About

What this is

LingoChallenge is a place to practice English grammar by filling in gaps. Every exercise is one sentence with one blank and one answer that fits. There are no accounts, no levels to unlock and no ads between questions.

How the sentences are checked

The practice pool holds over 50,000 sentences across more than 100 grammar forms. Every one of them has been read, not just generated.

The checking was done in passes, and each pass added rules the earlier ones had missed:

• Twenty automated checks run over the whole pool. They catch an empty answer, a missing gap, an answer that is already printed in the sentence, a case mismatch between the gap and its options, a question filed under a statements topic, and seventeen other faults.
• Every topic was then read in full, from the smallest to the largest. Machine checks find what they were told to look for; reading finds the rest — a key that is wrong, a sentence that does not assemble, a question that gives away its own answer.
• A sample audit followed, twenty records from every topic, run through the whole battery again. It found 163 further faults, almost all of them in topics closed early — the checks had grown as the work went on, and the first topics never met the later ones.

Where a topic turned out to be unanswerable by design — two options that are both correct because the sentence gives no way to choose — that was recorded rather than papered over.

Why the site looks like this

Practice comes before explanation. Most grammar sites put a wall of text first and hide the exercises at the bottom. If you arrived from a search for present perfect negative exercises, you want to start, not to read. So each page opens with the pattern, then the drill, and keeps the full explanation below for when you want it.

One gap, one answer. Where a question could be answered two ways, it is not a question. Every sentence in the pool is built so that the context forces a single answer — a clause that pins the frequency, a tense that pins the time, a number that pins the form.

The mistakes are named. Each page lists the errors learners actually make with that form, with the correction and the reason. Knowing why didn't went is wrong is worth more than being told that it is.

How it is built

A static site: the pages are plain files, and no server renders anything when you open one. The practice questions are the one exception — when you start a drill the page asks our own API for that set, rather than handing out the whole pool.

Corrections

If a sentence is wrong, we would rather know. Every report is checked against the same battery the rest of the pool goes through, and a genuine fault is fixed in the source, so it disappears from every page that used the sentence.

The small print

What the site records about your visit is on the privacy page. The rules for using the material are on the terms page.