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Help the panicked college student finish her excuse email to her professor by dragging the correct words into the gaps.

I am currently on the third floor of the library. I left my essay at home, and I am in a terrible panic! According to the syllabus, late work is penalized.

I am currently on the third floor of the library. I left my essay at home, and I am in a terrible panic! According to the syllabus, late work is penalized.

on: We use "on" for levels and floors of a building.

at: "At home" is a fixed phrase in English. Even though a house is an enclosed space, we don't say "in home".

a: "In a panic" or "in a hurry" are common expressions that require the indefinite article "a".

the: Both the student and the professor know which syllabus is being discussed, so it requires the definite article "the".

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Preposition

Prepositions form a closed word class, although there are also certain phrases that serve as prepositions, such as in front of.

A single preposition may have a variety of meanings, often including temporal, spatial and abstract. Many words that are prepositions can also serve as adverbs. Examples of common English prepositions (including phrasal instances) are of, in, on, over, under, to, from, with, in front of, behind, opposite, by, before, after, during, through, in spite of or despite, between, among, etc.

A preposition is usually used with a noun phrase as its complement.

A preposition together with its complement is called a prepositional phrase.

Examples are in England, under the table, after six pleasant weeks, between the land and the sea.

A prepositional phrase can be used as a complement or post-modifier of a noun in a noun phrase, as in the man in the car, the start of the fight; as a complement of a verb or adjective, as in deal with the problem, proud of oneself; or generally as an adverb phrase.

English allows the use of "stranded" prepositions. This can occur in interrogative and relative clauses, where the interrogative or relative pronoun that is the preposition's complement is moved to the start (fronted), leaving the preposition in place. This kind of structure is avoided in some kinds of formal English.

For example:

  • What are you talking about? (Possible alternative version: About what are you talking?)
  • The song that you were listening to ... (more formal: The song to which you were listening ...)

Notice that in the second example the relative pronoun that could be omitted.

Stranded prepositions can also arise in passive voice constructions and other uses of passive past participial phrases, where the complement in a prepositional phrase can become zero in the same way that a verb's direct object would: it was looked at; I will be operated on; get your teeth seen to.

The same can happen in certain uses of infinitive phrases: he is nice to talk to; this is the page to make copies of.

Article

Articles are a small group of determinatives that signal whether a noun refers to something specific or something general. English has just three: the definite article the and the indefinite articles a and an. There's also a meaningful absence — the zero article — where no article appears at all. Mastering articles is one of the trickiest parts of English, because the rules involve both grammar and context.

The Definite Article: the

Use the when you expect the listener or reader already knows which thing you mean. This could be because it was mentioned before, because the situation makes it obvious, or because there's only one.

  • I bought a jacket. The jacket was on sale.
  • Can you close the door?
  • The sun was setting behind the mountains.

The Indefinite Articles: a and an

Use a or an when introducing something for the first time or referring to any one member of a group. These only work with singular, countable nouns. Use a before consonant sounds and an before vowel sounds.

  • She adopted a dog.
  • He ate an apple.

The choice between a and an depends on the sound the next word starts with, not its spelling:

  • an honest mistake (silent h → vowel sound)
  • a honest mistake
  • a university (starts with a /j/ consonant sound)
  • an university

Self-check: Say the next word out loud. If it starts with a vowel sound, use an. Spelling can mislead you — trust your ear.

The Zero Article

The zero article means no article appears before the noun. This isn't random — it follows clear patterns.

Generic or indefinite plurals and mass nouns:

  • Coffee keeps me awake. (mass noun, general reference)
  • Cars need fuel. (plural, generic reference)

Certain institutions when used in their typical function:

  • She's in hospital. (as a patient — standard in British English)
  • He went to prison. (as an inmate)

When you mean the physical building rather than its function, add the:

  • The plumber went to the prison to fix the pipes.

Other common zero-article contexts:

  • Meals: Breakfast is ready.
  • Years: She was born in 1995.
  • Titles as complements: They elected her captain.

Quick Summary

ArticleUse it when…Example
theThe listener knows which onePass me the salt.
a / anIntroducing or generalising (singular, countable)I need a pen.
zero (∅)Generic plurals, mass nouns, institutions-as-functions, meals, yearsLife is short.

To put these rules into practice, try Articles Basics for core patterns, Articles: A, An, The & Zero Article for broader coverage, or Articles Advanced for trickier cases.

B2 | Upper Intermediate

B2, or Upper Intermediate, is the fourth level on the CEFR scale. It marks the point where you move from "getting by" to genuinely comfortable communication — handling complex topics, expressing nuanced opinions, and understanding most of what you read or hear in real-world contexts.

What a B2 user can do

At this level, you're expected to:

  • Understand complex texts on both concrete and abstract topics, including technical discussions in your own field.
  • Follow extended speech and lectures, even when the structure isn't entirely clear, as long as the topic is reasonably familiar.
  • Interact fluently and spontaneously enough that conversations with native speakers flow naturally — without strain on either side.
  • Produce clear, detailed text on a wide range of subjects, using connectors and cohesive devices to build well-structured arguments.
  • Explain and defend a viewpoint on a topical issue, weighing the advantages and disadvantages of different options.
  • Recognize implicit meaning — reading between the lines in demanding, longer texts.

What B2 grammar looks like in practice

B2 is where grammar stops being about isolated rules and starts being about flexibility and precision. You're expected to control structures like:

  • Advanced conditionals and mixed conditionals — moving beyond simple if-clauses to express hypothetical and counterfactual meaning.
  • Passive voice in varied tenses and contexts, not just present and past simple.
  • Reported speech with correct sequence of tenses, including backshifting and reporting verbs.
  • Participle clauses and the distinction between participles and gerunds.
  • Comparative and superlative structures beyond basic -er/-est, including double comparatives and qualifying expressions.

Errors still happen at B2, but they rarely cause misunderstanding. The goal is controlled, flexible use of language across social, academic, and professional settings.

How B2 fits in the CEFR progression

B2 builds directly on the foundations of B1 (Intermediate) and prepares you for C1 (Advanced). Many university entrance exams, professional certifications, and immigration requirements target B2 as the minimum standard.

Self-check: If you can read a newspaper editorial, follow most of a TED talk without subtitles, and write a clear essay arguing a position — you're likely operating at B2.

Ready to test yourself? Try Is your English level B2/Upper Intermediate? or practise specific B2 grammar with challenges like Basics. Advanced Conditionals And "wish", Basics. Passive Voice, and Sequence of Tenses in Indirect Speech.

Difficulty: Medium

Medium difficulty. Difficulty levels represent author's opinion about how hard a question or challenge is.