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.

Verb

Verbs constitute one of the main word classes in the English language. Like other types of words in the language, English verbs are not heavily inflected. Most combinations of tense, aspect, mood and voice are expressed periphrastically, using constructions with auxiliary verbs.

Generally, the only inflected forms of an English verb are a third person singular present tense form in -s, a past tense, a past participle (which may be the same as the past tense), and a form ending in -ing that serves as a present participle and gerund. Most verbs inflect in a simple regular fashion, although there are about 200 irregular verbs; the irregularity in nearly all cases concerns the past tense and past participle forms. The copula verb be has a larger number of different inflected forms, and is highly irregular.

A typical English verb may have five different inflected forms:

• The base form or plain form (go, write, climb), which has several uses—as an infinitive, imperative, present subjunctive, and present indicative except in the third-person singular
• The -s form (goes, writes, climbs), used as the present indicative in the third-person singular
• the past tense or preterite (went, wrote, climbed)
• The past participle (gone, written, climbed) – this is identical to the past tense in the case of regular verbs and some irregular ones (here the first two verbs are irregular and the third regular)
• The -ing form (going, writing, climbing), used as a present participle, gerund, and (de)verbal nounThe verb be has a larger number of different forms (am, is, are, was, were, etc.), while the modal verbs have a more limited number of forms.

Some forms of be and of certain other auxiliary verbs also have contracted forms (_ 's_, _ 're_, _ 've_, etc.).

In English, verbs frequently appear in combinations containing one or more auxiliary verbs and a nonfinite form (infinitive or participle) of a main (lexical) verb.

Examples

The first verb in such a combination is the finite verb, the remainder are nonfinite (although constructions in which even the leading verb is nonfinite are also possible – see below). Such combinations are sometimes called compound verbs; more technically they may be called verb catenae, since they are not generally strict grammatical constituents of the clause.

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

As the last example shows, the words making up these combinations do not always remain consecutive.

Tenses, Aspects and Moods

The means English uses for expressing the three categories of tense (time reference), aspect and mood are somewhat conflated. English has only limited means for expressing these categories through verb conjugation, and tends mostly to express them periphrastically, using the verb combinations mentioned in the previous section. The tenses, aspects and moods that may be identified in English are described below (although the terminology used differs significantly between authors). Note that in common usage, particular tense–aspect–mood combinations such as "present progressive" and "conditional perfect" are often referred to simply as "tenses".

Pronoun

Pronouns are a relatively small, closed class of words that function in the place of nouns or noun phrases. They include personal pronouns, demonstrative pronouns, relative pronouns, interrogative pronouns, and some others, mainly indefinite pronouns.

Personal

The personal pronouns of modern standard English, and the corresponding possessive forms, are as follows:

The second-person forms such as you are used with both singular and plural reference. You can also be used as an indefinite pronoun, referring to a person in general compared to the more formal alternative, one) (reflexive oneself, possessive one's).

The third-person singular forms are differentiated according to the sex of the referent. For example, she is used to refer to a female person, sometimes a female animal, and sometimes an object to which female characteristics are attributed, such as a ship or a country. A male person, and sometimes a male animal, is referred to using he. In other cases it can be used. The word it can also be used as a dummy subject, in sentences like It is going to be sunny this afternoon.

The third-person plural forms such as they are sometimes used with singular reference, as a gender-neutral pronoun, as in each employee should ensure they tidy their desk. Despite its long history, this usage is sometimes considered ungrammatical.

The possessive determiners such as my are used as determiners together with nouns, as in my old man, some of his friends. The second possessive forms like mine are used when they do not qualify a noun: as pronouns, as in mine is bigger than yours, and as predicates, as in this one is mine. Note also the construction a friend of mine (meaning "someone who is my friend").

Demonstrative and Interrogative

The demonstrative pronouns of English are this (plural these), and that (plural those), as in these are good, I like that. Note that all four words can also be used as determiners (followed by a noun), as in those cars. They can also form the alternative pronominal expressions this/that one, these/those ones.

The interrogative pronouns are who, what, and which (all of them can take the suffix -ever for emphasis). The pronoun who refers to a person or people; it has an oblique form whom (though in informal contexts this is usually replaced by who), and a possessive form (pronoun or determiner) whose. The pronoun what refers to things or abstracts. The word which is used to ask about alternatives from what is seen as a closed set: which (of the books) do you like best? (It can also be an interrogative determiner: which book?; this can form the alternative pronominal expressions which one and which ones.) Which, who, and what can be either singular or plural, although who and what often take a singular verb regardless of any supposed number.

All the interrogative pronouns can also be used as relative pronouns; see below for more details.

Relative

The main relative pronouns in English are who (with its derived forms whom and whose), which, and that.

The relative pronoun which refers to things rather than persons, as in the shirt, which used to be red, is faded. For persons, who is used (the man who saw me was tall). The oblique case form of who is whom, as in the man whom I saw was tall, although in informal registers who is commonly used in place of whom.

The possessive form of who is whose (the man whose car is missing ...); however the use of whose is not restricted to persons (one can say an idea whose time has come).

The word that as a relative pronoun is normally found only in restrictive relative clauses (unlike which and who, which can be used in both restrictive and unrestrictive clauses). It can refer to either persons or things, and cannot follow a preposition. For example, one can say the song that [or which] I listened to yesterday, but the song to which [not to that] I listened yesterday. The relative pronoun that is usually pronounced with a reduced vowel, and hence differently from the demonstrative that. If that is not the subject of the relative clause, it can be omitted (the song I listened to yesterday).

The word what can be used to form a free relative clause – one that has no antecedent and that serves as a complete noun phrase in itself, as in I like what he likes. The words whatever and whichever can be used similarly, in the role of either pronouns (whatever he likes) or determiners (whatever book he likes). When referring to persons, who(ever) (and whom(ever)) can be used in a similar way (but not as determiners).

"There"

The word there is used as a pronoun in some sentences, playing the role of a dummy subject, normally of an intransitive verb. The "logical subject" of the verb then appears as a complement after the verb.

This use of there occurs most commonly with forms of the verb be in existential clauses, to refer to the presence or existence of something. For example: There is a heaven; There are two cups on the table; There have been a lot of problems lately. It can also be used with other verbs: There exist two major variants; There occurred a very strange incident.

The dummy subject takes the number (singular or plural) of the logical subject (complement), hence it takes a plural verb if the complement is plural. In informal English, however, the contraction there's is often used for both singular and plural.

The dummy subject can undergo inversion, Is there a test today? and Never has there been a man such as this. It can also appear without a corresponding logical subject, in short sentences and question tags: ''There wasn't a discussion, was there? There was.''

The word there in such sentences has sometimes been analyzed as an adverb, or as a dummy predicate, rather than as a pronoun. However, its identification as a pronoun is most consistent with its behavior in inverted sentences and question tags as described above.

Because the word there can also be a deictic adverb (meaning "at/to that place"), a sentence like There is a river could have either of two meanings: "a river exists" (with there as a pronoun), and "a river is in that place" (with there as an adverb).

Other

Other pronouns in English are often identical in form to determiners (especially quantifiers), such as many, a little, etc. Sometimes, the pronoun form is different, as with none (corresponding to the determiner no), nothing, everyone, somebody, etc. Many examples are listed as indefinite pronouns. Another indefinite (or impersonal) pronoun is one) (with its reflexive form oneself and possessive one's), which is a more formal alternative to generic you.

B1 / Intermediate

A CEFR B1 level English language user is considered to be at an intermediate level. A B1 level English language user is expected to have the following abilities:

• Can understand sentences and frequently used expressions related to areas of most immediate relevance (e.g. very basic personal and family information, shopping, local geography, employment).
• Can communicate in simple and routine tasks requiring a simple and direct exchange of information on familiar and routine matters.
• Can describe in simple terms aspects of their background, immediate environment and matters in areas of immediate need.
• Can understand the main points of clear standard input on familiar matters regularly encountered in work, school, leisure, etc.
• Can produce simple connected text on topics that are familiar or of personal interest.
• Can describe experiences and events, dreams, hopes & ambitions and briefly give reasons and explanations for opinions and plans.

At B1 level, English language users are expected to have a basic level of proficiency in the language. They should be able to understand and produce language in simple and routine tasks, and be able to communicate in familiar and routine matters. They should be able to understand the main points of clear standard input on familiar matters and be able to produce simple connected text on topics that are familiar or of personal interest. They are able to express themselves with a degree of fluency, but with some hesitation, and occasional errors in grammar and vocabulary.

B1 | Intermediate.

Difficulty: Medium

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