The correct answers are The main computer crashed, and it refuses to reboot., I lost my favorite wrench, but I think it is under the console., and The spaceship is old, but it still flies perfectly.
Slavic languages assign grammatical gender (masculine, feminine, neuter) to inanimate objects, leading speakers to accidentally call a computer "he" or a wrench "she." In English, almost all inanimate objects and concepts take the neutral pronoun it.
Pronoun
If you've ever paused before who vs whom, its vs it's, or me vs I — you've felt how much weight pronouns carry in English. They're tiny words but they're case-sensitive (I vs me), context-dependent, and one of the few places where everyday English still trips careful speakers. Get the common patterns right and you instantly sound more careful.
A pronoun is a closed class of small words that replace nouns or noun phrases. Types: personal (I, you, he…), demonstrative (this, that), relative (who, which), interrogative (who?, what?), reflexive (myself), and indefinite (everyone, nobody).
Subject
If you've ever written The list of items are wrong (should be is wrong) — you've hit the subject-agreement trap. The subject is list, not items, and the verb has to agree with it. Long sentences with prepositional phrases between the subject and verb are where this most often goes wrong, and getting it right is what stops careful readers from flagging your writing.
The subject is the part of a sentence or clause that says who or what the sentence is about. Typically a noun, pronoun, or noun phrase before the verb, controlling the verb's number and person.
Sentence
If your writing has been called "choppy" or "monotonous", the issue is usually sentence variety — not vocabulary. English readers expect a mix of short and long, simple and complex sentences. Even the same content reads completely differently depending on how you stitch the clauses together.
A sentence is the largest grammatical unit, made of one or more clauses. Four structural types: simple (one independent clause), compound (two+ independents joined), complex (independent + dependent), compound-complex (multiple of each). Ends with period, question mark, or exclamation mark.
B1 | Intermediate
If you can hold a conversation about your weekend, explain why you're late, and follow a short news story without panicking — but still feel lost in fast or technical English — you're probably operating at B1. Knowing this matters: study material at the wrong level either bores you or burns you out, and B1 is the typical target for travel, casual work, and most everyday social English.
B1 is the intermediate level in the CEFR framework, where you handle everyday English independently and start combining ideas with complex sentences, passive voice, and modal verbs.
Difficulty: Medium
If easy questions feel too obvious but hard questions leave you guessing, you're probably ready for Medium — the level where most real learning happens. It pushes just enough to expose the rules you don't quite have yet, without burying you in edge cases. This is where steady fluency is built, one well-aimed challenge at a time.
The Medium difficulty tag marks middle-range challenges — typically A2 to B1. One rule per question, realistic distractors, and contexts that require active thought rather than instant recognition.