Choose the correct word to complete the eccentric billionaire's last will and testament.
"I stipulate that my beloved pet penguin, Sir Waddles, _____ fed only the finest imported caviar every morning."
The correct answer is be.
Formal verbs of commanding or stipulating (like "stipulate", "demand", or "order") require the base form of the verb in the that-clause. For the verb "to be", the base form is simply "be", even for third-person singular subjects like "Sir Waddles".
Subjunctive mood
The subjunctive mood is the verb form English uses for hypothetical, counterfactual, or formal-recommendation contexts. The two main patterns are: the present subjunctive in that-clauses after verbs of recommendation/insistence (I suggest that he go, It's essential that she be informed), and the past subjunctive were in counterfactual conditionals (If I were you).
Most subjunctive forms in modern English look identical to the indicative — the visible signs are the missing third-person -s (he go, not he goes) and were with first/third-person singular (if I were). Easy to miss; a strong marker of careful, formal English when used.
Verb mood
Verb mood is the verb form that signals the speaker's attitude toward the action — whether it's a fact, a command, a hypothetical, or a recommendation. English has four main moods: indicative for statements and questions about facts (She works here), imperative for commands and instructions (Sit down!), subjunctive for hypothetical or formal-recommendation contexts (If I were you; I suggest he go), and conditional for would/could constructions (I would go).
Most English sentences are indicative — that's the default. The other three moods are smaller categories, but each marks a specific shift in meaning that can't be expressed any other way.
Clause
A clause is a grammatical unit built around a verb — typically a subject plus a predicate (She laughed; The manager approved the budget). Clauses come in two types: independent clauses stand alone as complete sentences; dependent clauses need an independent clause to make sense (Because I overslept — incomplete on its own).
Spotting clause boundaries is the foundation of correct punctuation. Once you can see where one clause ends and another begins, comma rules, run-on sentences, and complex sentence structure stop being mysteries.
Verb
A verb is a word that expresses an action, a state, or an occurrence — the engine of every English sentence. Most verbs have five forms: base (go), -s form (goes), past tense (went), past participle (gone), and -ing form (going). The verb be is the major exception with eight forms; modal verbs like can and must have fewer.
Verbs carry tense (when), aspect (how it unfolds), mood (the speaker's attitude), and voice (active vs passive). Mastering them is foundational — virtually every other grammar topic depends on getting verbs right.
C1 | Advanced
C1 is the advanced level in the CEFR framework, sitting between B2 and C2. At C1 you stop translating in your head and start thinking in English — handling specialised articles outside your field, picking up implicit meaning, and writing structured arguments on complex topics.
Grammatically, C1 means natural use of inversion (Rarely have I seen…), mixed and advanced conditionals, subjunctive forms in formal contexts, and cleft sentences for emphasis. Most university programmes for non-native speakers and many professional certifications set C1 as their entry standard.
Difficulty: Hard
The Hard difficulty tag marks questions and challenges aimed at upper-intermediate to advanced learners — typically B2 and above. Expect interacting rules, edge cases, distractors that look right at first glance, and contexts where the surface meaning and the grammatical answer don't match.
Filter by Hard when you're past the basics and want material that genuinely tests your understanding. These questions catch the gaps your textbook didn't — register-sensitive choices, exception cases, mixed conditionals, the difference between would have been and had been.