Complete the time-traveler's survival guide by matching the correct actions to the scenarios. Pay close attention to the second half of each sentence!

If you press the red button now, the time machine will launch us into the future. If a dinosaur chased you, you would need to run very fast! If we had packed more snacks, we wouldn't have gone hungry in the Jurassic period.

If you press the red button now, the time machine will launch us into the future.

The main clause uses "will launch" (First Conditional), so the "if" clause needs the present simple tense ("press") for a possible future action.

If a dinosaur chased you, you would need to run very fast!

The main clause uses "would need" (Second Conditional), so the "if" clause requires the past simple tense ("chased") for a hypothetical or unlikely situation.

If we had packed more snacks, we wouldn't have gone hungry in the Jurassic period.

The main clause uses "wouldn't have gone" (Third Conditional), so the "if" clause must use the past perfect tense ("had packed") to describe an unreal past condition.

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Conditional Sentence

As is typical for many languages, full conditional sentences in English consist of a condition clause or protasis specifying a condition or hypothesis, and a consequence clause or apodosis specifying what follows from that condition. The condition clause is a dependent clause, most commonly headed by the conjunction if, while the consequence is contained in the main clause of the sentence. Either clause may appear first.

Different types of conditional sentences (depending largely on whether they refer to a past, present or future time frame) require the use of particular verb forms (tenses and moods) to express the condition and the consequence. In English language teaching the most common patterns are referred to as first conditional, second conditional and third conditional; there is also a zero conditional and mixed conditional.

Present

Present tense is used, in principle, to refer to circumstances that exist at the present time (or over a period that includes the present time) and general truths. However the same forms are quite often also used to refer to future circumstances, as in "He's coming tomorrow" (hence this tense is sometimes referred to as present-future or nonpast). For certain grammatical contexts where the present tense is the standard way to refer to the future, e.g., conditional sentences and dependent clauses. It is also possible for the present tense to be used when referring to no particular real time (as when telling a story), or when recounting past events (the historical present, particularly common in headline language). The present perfect intrinsically refers to past events, although it can be considered to denote primarily the resulting present situation rather than the events themselves.

The present tense has two moods, indicative and subjunctive; when no mood is specified, it is often the indicative that is meant. In a present indicative construction, the finite verb appears in its base form, or in its -s form if its subject is third-person singular. (The verb be has the forms am, is, are, while the modal verbs do not add -s for third-person singular.)

Past

Past tense forms express circumstances existing at some time in the past, although they also have certain uses in referring to hypothetical situations (as in some conditional sentences, dependent clauses and expressions of wish). They are formed using the finite verb in its preterite (simple past) form.

Certain uses of the past tense may be referred to as subjunctives; however the only distinction in verb conjugation between the past indicative and past subjunctive is the possible use of were in the subjunctive in place of was.

Note also that in certain contexts past events are reported using the present perfect.

Future

English is sometimes described as having a future tense, although since future time is not specifically expressed by verb inflection, some grammarians identify only two tenses (present or present-future, and past). The English "future" usually refers to a periphrastic form involving the auxiliary verb will (or sometimes shall when used with a first-person subject). There also exist other ways of referring to future circumstances, including the going to construction, and the use of present tense forms. For particular grammatical contexts where the present tense substitutes for the future, see conditional sentences and dependent clauses. For discussion and comparison of the various ways of making future reference in English, see going-to future.

For specific uses of future constructions formed with will/shall, see future.

Future-in-the-past

A "future-in-the-past" tense (or form) is sometimes referred to. This takes essentially the same form as the conditional, that is, it is made using the auxiliary would (or sometimes should in the first person).

This form has a future-in-the-past meaning in sentences such as She knew that she would win the game. Here the sentence as a whole refers to some particular past time, but would win refers to a time in the future relative to that past time.

Verb

A verb is a word that expresses an action, a state, or an occurrence — and it's the engine of every English sentence. Understanding how verbs work is foundational to everything else in English grammar, from forming questions to building complex sentences.

Verb Forms

Most English verbs have five inflected forms:

  • Base form (go, write, climb) — used as an infinitive, imperative, present subjunctive, and present indicative in all persons except third-person singular.
  • -s form (goes, writes, climbs) — used for the present tense, third-person singular (she writes).
  • Past tense (went, wrote, climbed) — also called the preterite.
  • Past participle (gone, written, climbed) — identical to the past tense for regular verbs, but often different for irregular verbs.
  • -ing form (going, writing, climbing) — serves as the present participle and gerund.

The verb be is a special case with more forms than any other English verb (am, is, are, was, were, been, being). Modal verbs like can, must, and should have fewer forms than typical verbs.

Main Verbs and Auxiliaries

Verbs in English often appear in combinations: one or more auxiliary verbs paired with a main verb.

  • The dog was barking very loudly.
  • My hat has been cleaned.
  • Jane does not really like us.

The first verb in the combination is the finite verb (it carries tense and agrees with the subject). The rest are nonfinite (infinitives or participles). Notice that these verbs don't always sit next to each other — as in does not really like.

Tense, Aspect, and Mood

English expresses tense (time reference), aspect (how an action unfolds over time), and mood (the speaker's attitude toward the action) mostly through verb combinations rather than word endings. That's why you'll encounter labels like "present progressive" or "conditional perfect" — these are specific tense–aspect–mood combinations built with auxiliaries.

Self-check: If you can change the time of a sentence by swapping one word (She runs → She ran), that word is the verb.

Keep Practising

To build your verb skills from the ground up, try these challenges: Basics. "To be" in Present Tense, Basics. Common Uses of Auxiliary Verbs, and Transitive and Intransitive Verbs.

Clause

A clause is a grammatical unit built around a verb that typically contains a subject and a predicate. Understanding clauses is essential because they are the core building blocks of every sentence you read, write, or speak.

What makes a clause?

At minimum, a clause needs a verb (the predicate) and, in most cases, a subject — the person or thing the verb says something about. The predicate can also include objects, complements, and modifiers.

  • She laughed. — subject (she) + verb (laughed)
  • The manager approved the budget yesterday. — subject + verb + object + modifier

Sometimes the subject is left out. This happens regularly in imperative sentences and non-finite clauses:

  • Sit down. — no visible subject, but "you" is understood
  • Walking home, I noticed the shop was closed. — the -ing clause has no stated subject

Types of clauses

There are two main types:

  • Independent clause (also called a main clause) — can stand on its own as a complete sentence. It contains a finite verb.

    • I missed the bus.
  • Dependent clause (also called a subordinate clause) — cannot stand alone and needs an independent clause to make sense.

    • Because I overslept — incomplete on its own

Combine them and you get a complex sentence:

  • I missed the bus because I overslept.

A simple sentence has one independent clause. More complex sentences combine independent and dependent clauses in various ways.

Quick check: If you can remove a group of words from a sentence and it still has a subject + finite verb and makes sense on its own, that group is likely an independent clause.

Why clauses matter

Recognizing clause boundaries helps you punctuate correctly, avoid run-on sentences, and build more varied, natural-sounding writing. Once you can spot where one clause ends and another begins, sentence structure becomes much easier to manage.

Ready to practice? Try Complex Sentence for the basics, then move on to Complex Sentence: Adverbials or Participle Clauses: Shortening Sentences with -ing and Having + Past Participle to deepen your skills.

Humor

Humor is subjective, but at least the author tried.

B1 | Intermediate

B1 is the intermediate level of the Common European Framework of Reference for Languages (CEFR). It marks the point where you move beyond survival English and start expressing yourself with real independence — describing experiences, explaining opinions, and handling everyday situations without a script.

What a B1 user can do

At this level, you're expected to:

  • Understand the main points of clear, standard speech and writing on familiar topics — work, school, travel, hobbies.
  • Handle most travel situations in English-speaking environments.
  • Produce simple connected text on topics you know or care about.
  • Describe experiences, events, hopes, and plans, and give brief reasons and explanations for your opinions.
  • Communicate in routine tasks that require a straightforward exchange of information.

What B1 grammar looks like

B1 is where grammar starts to get more layered. You're not just forming basic sentences anymore — you're combining ideas, using different tenses with more precision, and starting to handle structures like the passive voice, modal verbs for necessity and possibility, and gerunds vs. infinitives. You're also expected to build complex sentences with linking words and dependent clauses.

Typical B1 grammar areas include:

  • Future tenses — distinguishing will, going to, and the present continuous for future plans
  • Passive voiceThe report was written yesterday.
  • Modal verbsYou should apply early. / She might be late.
  • Used toI used to live in Berlin.
  • Verb patterns — knowing whether a verb takes a gerund, an infinitive, or both (I enjoy reading vs. I decided to leave)

What B1 doesn't mean

B1 speakers still hesitate, make grammatical errors, and sometimes struggle with less familiar topics. That's normal. The key difference from A2 is that you can keep a conversation going and get your point across even when things aren't perfect. The step up to B2 involves handling more abstract topics, understanding nuance, and producing more complex, accurate language.

Self-check: Can you tell a friend about a recent trip — what happened, what you liked, and what you'd do differently — without switching to your native language? If yes, you're likely operating at B1 or above.

Ready to find out where you stand? Try Are you B1/Intermediate? Test your English CEFR Level to figure out!, then build your skills with challenges like Basics. Passive Voice, Basics. Modal verbs, and Used to.

Difficulty: Medium

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