The correct answers are I wrote the essay, but my cat deleted the file. and I printed the assignment and placed it on your desk.
But is used to show contrast or an unexpected problem (writing the essay vs. the cat deleting it).
And is used to link two related actions together (printing and placing).
The incorrect options use two conjunctions right next to each other ("but because", "but and"), which is grammatically incorrect.
Conjunction
If your writing reads like a list of separate sentences — I was tired. I went home. I slept badly. — the missing piece is conjunctions. They're how you bind ideas together: I was tired, so I went home, but I still slept badly. Pick the wrong one and the relationship between ideas flips; pick none and your writing stays choppy.
A conjunction connects words, phrases, or clauses. Coordinating conjunctions (and, but, or, so, yet, for, nor) link equal units; subordinating conjunctions (because, although, if, when, while) introduce dependent clauses.
Coordination
If you've ever stared at a list and not known whether to use and or a comma, or whether the items in your list need to be parallel — you've hit the rules of coordination. Get them right and your sentences flow; miss them and your reader stumbles over awkward constructions like I like reading, swim, and to cook.
Coordination links two or more elements of equal grammatical weight using a coordinating conjunction — and, or, but. The linked items must be the same kind of thing: noun + noun, clause + clause, verb phrase + verb phrase. Mismatched items make the sentence sound clearly off.
Compound sentence
If you've ever been told you've written a "comma splice", you've hit the most common compound-sentence trap. The sun was shining, everyone appeared happy — looks fine, reads fine, but technically wrong. Once you can spot independent clauses, this error becomes obvious and easy to fix three different ways.
A compound sentence joins two or more independent clauses, each a complete thought. The link is a coordinating conjunction (and, but, or, so, yet) with a comma, or a semicolon on its own: I started on time, but I arrived late.
A2 | Elementary | Pre-intermediate
If you can order coffee, ask for directions, and tell someone what you did yesterday — but struggle the moment the conversation drifts into anything abstract — you're operating at A2. Knowing this matters: A2 is the level where most learners plateau because they reach for B2 material too early and burn out. Stay here and your foundations get unbreakable.
A2 is the elementary level in the CEFR framework, covering routine communication and the first wave of real grammar: past simple and continuous, present perfect, basic modal verbs, first conditional, and common verb-pattern rules.
Difficulty: Easy
If a textbook leaves you confused, sometimes the issue isn't the topic — it's that the practice material is layered with extra complications. Filtering by Easy strips that away. You get one rule at a time, in plain everyday language, with no trick questions. It's how you make a shaky foundation solid before stacking more on top.
The Easy difficulty tag marks beginner-level questions and challenges — typically A1 or early A2. Single-rule focus, short sentences, common vocabulary, one clear correct answer.