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Drag the correct verb forms to complete the Time Traveler's Safety Guide.

As a time traveler, you had better blend in with the locals, or you will permanently alter history! Furthermore, the Agency would rather you didn't talk to your past self under any circumstances.

As a time traveler, you had better blend in with the locals, or you will permanently alter history!

"Had better" is used for strong warnings and is always followed by the bare infinitive (the base verb without "to").

Furthermore, the Agency would rather you didn't talk to your past self under any circumstances.

When "would rather" is followed by a different subject (the Agency would rather you...), we use the past tense to express the preference. The correct negative past form here is "didn't".

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Modal Verb

English has the modal verbs can, could, may, might, must, shall, should, will, would, and also (depending on classification adopted) ought (to), dare, need, had (better), used (to). These do not add -s for the third-person singular, and they do not form infinitives or participles; the only inflection they undergo is that to a certain extent could, might, should and would function as preterites (past tenses) of can, may, shall and will respectively.

A modal verb can serve as the finite verb introducing a verb catena, as in "he might have been injured then". These generally express some form of modality (possibility, obligation, etc.), although will and would (and sometimes shall and should) can serve – among their other uses – to express future time reference and conditional mood.

Subjunctive Mood

The subjunctive mood in English is used to form sentences that do not describe known objective facts, but rather wishes or hypothetical suppositions. These include statements about one's state of mind, such as opinion, belief, purpose, intention, or desire. The subjunctive mood, such as She suggests that he speak English, contrasts with the indicative mood, which is used for statements of fact, such as He speaks English.

In Modern English, the subjunctive form of a verb often looks identical to the indicative form, and thus subjunctives are not a very visible grammatical feature of English. For most verbs, the only distinct subjunctive form is found in the third person singular of the present tense, where the subjunctive lacks the -s ending: It is necessary that he see a doctor (contrasted with the indicative he sees). The verb be, however, has not only a distinct present subjunctive (be, as in I suggest that he be removed) but also a past subjunctive were (as in If he were rich, ...).

These two tenses of the subjunctive have no particular connection in meaning with present and past time. Terminology varies; sometimes what is called the present subjunctive here is referred to simply as the subjunctive, and the form were may be treated just as an alternative irrealis form of was rather than a past subjunctive.

Another case where present-subjunctive forms are distinguished from indicatives is when they are negated: compare I recommend that they not enter the competition (subjunctive) with I hope that they do not enter the competition (indicative).

Past Subjunctive Mood

The only distinct past subjunctive form in English (i.e., form that differs from the corresponding past indicative) is were, which differs when used with a first or third person singular subject (where the indicative form is was). As with the present subjunctive, the name past subjunctive refers to the form of the verb rather than its meaning; it need not (and in fact usually does not) refer to past time. The main use of the past subjunctive form, were, which is also known as the irrealis is in counterfactual if clauses:

  • If I were your wife, I would put poison in your coffee. [Attributed to Lady Astor, speaking to Winston Churchill]

The simple (indicative) past form was is very common in sentences of this type, though the Random House College Dictionary states "Although the [were] subjunctive seems to be disappearing from the speech of many, its proper use is still a mark of the educated speaker." When were is used, an inverted form without if is possible; this is not possible with was.

A common expression involving were is if I were you. The same principles of usage apply to the compound past subjunctive form were to..., which appears in second conditional condition clauses, usually with hypothetical future reference:

  • If she were to go... or Were she to go... (equivalent to if she went)

The past subjunctive form may be used similarly to express counterfactual conditions after suppose, as if, as though, unless, imagine etc.

  • Suppose that I were there now.
  • She looks as though she were going to kill him.
  • Try to imagine he were here.
  • Try to imagine a tool that** made** that easy for citizens.

There is also the set expression as it were.

The past subjunctive can also be used in some that clauses expressing a wish contrary to fact or unlikely to be fulfilled:

  • I wish [that] he were here now.
  • If only the door were unlocked.
  • I would rather [that] she were released.
  • Would that it were true!
  • Oh that it were so.

However, the use of the subjunctive with words such as wish is seldom obligatory. The example with would rather can be cast in the present subjunctive, expressing greater confidence that the action is feasible:

  • I would rather she be released.

Infinitive

Regarding English, the term infinitive is traditionally applied to the unmarked form of the verb when it forms a non-finite verb, whether or not introduced by the particle to.

Hence sit and to sit, as used in the following sentences, would each be considered an infinitive:

  • I can sit here all day.
  • I want to sit on the other chair.

The form without to is called the bare infinitive; the form introduced by to is called the full infinitive or to-infinitive.

The other non-finite verb forms in English are the gerund or present participle (the -ing form), and the past participle – these are not considered infinitives.

Moreover, the unmarked form of the verb is not considered an infinitive when it is forms a finite verb: like a present indicative ("I sit every day"), subjunctive ("I suggest that he sit"), or imperative ("Sit down!"). (For some irregular verbs the form of the infinitive coincides additionally with that of the past tense and/or past participle, like in the case of put.)

Certain auxiliary verbs are defective in that they do not have infinitives (or any other non-finite forms).

This applies to the modal verbs (can, must, etc.), as well as certain related auxiliaries like the had of had better and the used of used to. (Periphrases can be employed instead in some cases, like (to) be able to for can, and (to) have to for must.) It also applies to the auxiliary do, like used in questions, negatives and emphasis like described under do-support. Infinitives are negated by simply preceding them with not.

Of course the verb do when forming a main verb can appear in the infinitive. However, the auxiliary verbs have (used to form the perfect) and be (used to form the passive voice and continuous aspect) both commonly appear in the infinitive: "I should have finished by now"; "It's thought to have been a burial site"; "Let him be released"; "I hope to be working tomorrow."

Perfect Infinitive

There are nonfinite constructions that are marked for perfect, progressive or perfect progressive aspect, using the infinitives, participles or gerunds of the appropriate auxiliaries. The meanings are as would be expected for the respective aspects: perfect for prior occurrence, progressive for ongoing occurrence at a particular time. (Passive voice can also be marked in nonfinite constructions – with infinitives, gerunds and present participles – in the expected way: (to) be eaten, being eaten, having been eaten, etc.)

Examples of nonfinite constructions marked for the various aspects are given below.

Bare infinitive:

  • You should have left earlier. (perfect infinitive; for similar constructions and their meanings see modal verbs)
  • She might be revising. (progressive; refers to an ongoing action at this moment)
  • He must have been working hard. (perfect progressive; i.e. I assume he has been working hard)

To-infinitive:

  • He is said to have resigned. (perfect infinitive)
  • I expect to be sitting here this time tomorrow. (progressive)
  • He claims to have been working here for ten weeks. (perfect progressive)

Present participle:

  • Having written the letter, she went to bed. (perfect)
  • The man having left, we began to talk. (perfect, in a nominative absolute construction)
  • Having been standing for several hours, they were beginning to feel tired. (perfect progressive)

Past participle:

  • We have been waiting a long time. (progressive, used only as part of a perfect progressive construction)

Gerund:

  • My having caught the spider impressed the others. (perfect)
  • We are not proud of having been drinking all night. (perfect progressive)

Other aspectual, temporal and modal information can be marked on nonfinite verbs using periphrastic constructions. For example, a "future infinitive" can be constructed using forms such as (to) be going to eat or (to) be about to eat.

Negation

A finite indicative verb (or its clause) is negated by placing the word not after an auxiliary, modal or other "special" verb such as do, can or be. For example, the clause I go is negated with the appearance of the auxiliary do, as I do not go. When the affirmative already uses auxiliary verbs (I am going), no other auxiliary verbs are added to negate the clause (I am not going). (Until the period of early Modern English, negation was effected without additional auxiliary verbs: I go not.)

Most combinations of auxiliary verbs etc. with not have contracted forms: don't, can't, isn't, etc. (Also the uncontracted negated form of can is written as a single word cannot.) On inversion of subject and verb (such as in questions), the subject may be placed after a contracted negated form: Should he not pay? or Shouldn't he pay?

Other elements, such as noun phrases, adjectives, adverbs, infinitive and participial phrases, etc., can be negated by placing the word not before them: not the right answer, not interesting, not to enter, not noticing the train, etc.

When other negating words such as never, nobody, etc. appear in a sentence, the negating not is omitted (unlike its equivalents in many languages): I saw nothing or I didn't see anything, but not (except in non-standard speech) I didn't see nothing. Such negating words generally have corresponding negative polarity items (ever for never, anybody for nobody, etc.) which can appear in a negative context, but are not negative themselves (and can thus be used after a negation without giving rise to double negatives).

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.

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.