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.

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.

English Grammar Basics

"English Grammar Basics" tag marks quiz and explainers that intend to provide a solid foundation in English language grammar. This includes all the major concepts and topics in English grammar, including nouns, verbs, adjectives, adverbs, prepositions, conjunctions, tenses, voice, mood, and sentence structure. The explanations we provide in quiz intro sections are clear and concise, making it easy for learners of all levels to understand. These quizzes are designed to be fun and engaging, helping you to retain the information more effectively. Whether you're a beginner or looking to refresh your knowledge, look for content marked with the "English Grammar Basics" tag for everything you need to master English language grammar.

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 voice — The report was written yesterday.
• Modal verbs — You should apply early. / She might be late.
• Used to — I 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.