The correct answers are "I visited my grandmother last Tuesday." and "I haven't seen her since December."
In many Romance languages, you can use the present perfect with specific past times (like last Tuesday). However, in English, finished time periods always require the Past Simple ("I visited").
When an action starts in the past and continues to the present (indicated by since or for), English requires the Present Perfect ("I haven't seen her").
Past tense
The past tense is how English talks about events finished before now. It comes in four flavours: simple past (I walked) for completed events, past progressive (I was walking) for actions ongoing at a past time, past perfect (I had walked) for events before another past event, and past perfect progressive (I had been walking) for ongoing events leading up to a past point.
Choosing the right one is what makes past narratives clear instead of murky. When I arrived, she ate dinner is technically grammatical but means something different than had eaten (already done) or was eating (in progress when you arrived).
Perfect tense
The perfect aspect marks an action as complete relative to a point in time. It's formed with have + past participle: I have eaten (present perfect), She had finished (past perfect), They will have arrived (future perfect). The perfect doesn't just say when — it says the action's completion is relevant to the time of reference.
The trickiest English-specific use is the present perfect: I have lived in Paris connects the past to now (you may still live there), while I lived in Paris doesn't. This connection is one of the biggest jumps for learners whose native language doesn't make the same distinction.
Simple tense
The simple aspect is the unmarked verb form — no progressive -ing, no have + past participle. I go, I went, I will go are simple; I am going, I have gone, I had gone are not. The simple aspect typically marks a single completed action (Brutus killed Caesar), a repeated/habitual action (I go to school every day), or a permanent state (We live in Dallas).
The simple aspect is the foundation everything else builds on. Once it's automatic, switching into progressive (ongoing) or perfect (completed-relative-to-now) becomes a small adjustment rather than a fresh decision.
B1 | Intermediate
B1 is the intermediate level in the CEFR framework — the point where you stop relying on memorised phrases and start handling everyday English independently. At B1 you can describe experiences, explain opinions, and follow most clear standard speech on familiar topics like work, travel, and hobbies.
Grammatically, B1 means combining tenses with precision, building complex sentences, and starting to use passive voice, modal verbs for necessity and possibility, and verb patterns (gerund vs. infinitive). Knowing your level shapes what you study next: pushing too far ahead frustrates you; staying below your level wastes time.
Difficulty: Medium
The Medium difficulty tag marks questions and challenges in the middle of the difficulty range — typically suitable for A2 to B1 learners. Expect a single rule with realistic distractors, longer sentences, and contexts where you have to think before answering rather than reading off the obvious choice.
Filter by Medium when you're past the absolute basics and ready to consolidate. It's the level where most lasting progress happens — easy enough that you can finish without exhausting concentration, hard enough that getting it right means you've actually understood.