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.

Relative Clause

A relative clause is a kind of subordinate clause that contains the element whose interpretation is provided by an antecedent on which the subordinate clause is grammatically dependent; that is, there is an anaphoric relation between the relativized element in the relative clause and antecedent on which it depends.

Typically, a relative clause modifies a noun or noun phrase, and uses some grammatical device to indicate that one of the arguments within the relative clause has the same referent as that noun or noun phrase. For example, in the sentence *I met a man who wasn't there*, the subordinate clause who wasn't there is a relative clause, since it modifies the noun man, and uses the pronoun who to indicate that the same "man" is referred to within the subordinate clause (in this case, as its subject).

In many European languages, relative clauses are introduced by a special class of pronouns called relative pronouns, such as who in the example just given.

Restrictive and Non-restrictive

Bound relative clauses may or may not be restrictive. Whereas a non-restrictive or non-defining relative clause merely provides supplementary information, a restrictive or defining relative clause modifies the meaning of its head word (restricts its possible referent).

For example:

• *The man who lives in this house has not been seen for days*. This (*who lives in this house*) is a restrictive relative clause, modifying the meaning of man, and essential to the sentence (if the clause were omitted, it would no longer be known which man is being referred to). If the bold part is deleted the remaining part does not provide the sense.
• The mayor, who lives in this house, has not been seen for days. This is a non-restrictive relative clause, since it provides supplementary information about the mayor, but is not essential to the sentence – if the clause were omitted, it would still be known which mayor is meant. If the bold part is deleted the remaining part provides the sense. In speaking it is natural to make slight pauses around non-restrictive clauses, and in English this is shown in writing by commas (as in the examples).

Another difference in English is that only restrictive relative clauses may be introduced with that or use the "zero" relative pronoun. In colloquial speech, a non-restrictive relative clause may have a whole sentence as its antecedent rather than a specific noun phrase; for example:

• *The cat was allowed on the bed, which annoyed the dog*.

Here, the context of the sentence (presumably) indicates that which refers not to the bed or the cat but to the entire proposition expressed in the main clause, namely the circumstance that the cat was allowed on the bed. Such constructions are discouraged in formal usage and in texts written for nonnative speakers because of the potential for ambiguity in parsing; a construction more accepted in formal usage would be The cat's being [or having been] allowed on the bed annoyed the dog.

Finite and Non-Finite

Relative clauses may be either finite clauses (as in the examples above) or non-finite clauses. An example of a non-finite relative clause in English is the infinitive clause on whom to rely, in the sentence "She is the person on whom to rely".

Relative Clauses in English

In English, a relative clause follows the noun it modifies. It is generally indicated by a relative pronoun at the start of the clause, although sometimes simply by word order. If the relative pronoun is the object of the verb in the relative clause, it comes at the beginning of the clause even though it would come at the end of an independent clause ("He is the man whom I saw", not "He is the man I saw whom"). The choice of relative pronoun can be affected by whether the clause modifies a human or non-human noun, by whether the clause is restrictive or not, and by the role (subject, direct object, or the like) of the relative pronoun in the relative clause.

• For a human antecedent, "who", "whom", or "that" is usually used ("He is the person who saw me", "He is the person whom I saw", "He is the person that I saw"). For a non-human antecedent, only "that" or "which" is used.
• For a non-human antecedent in a non-restrictive clause, only "which" is used ("The tree, which fell, is over there"); while either "which" or "that" may be used in a restrictive clause ("The tree which fell is over there", "The tree that fell is over there")—but some styles and prescriptive grammars require the use of "that" in the restrictive context.
• Of the relative pronoun pair "who" and "whom", the subjective case form ("who") is used if it is the subject of the relative clause ("He is the policeman who saw me"); and, in formal usage, the objective case form ("whom") if it is the object of the verb or preposition in the relative clause ("He is the policeman whom I saw", "He is the policeman whom I talked to", "He is the policeman to whom I talked"); but in informal usage "whom" is often replaced by "who".

In English, non-restrictive relative clauses are set off with commas, but restrictive ones are not:

• "I met a man and a woman yesterday. The woman, who had a thick French accent, was very pretty." (non-restrictive—does not narrow down who is being talked about)
• "I met two women yesterday, one with a thick French accent and one with a mild Italian one. The woman who had the thick French accent was very pretty." (restrictive—adds information about who is being referred to)The status of "that" as a relative pronoun is not universally agreed.

Independent clause

An independent clause (or main clause) is a clause that can stand by itself as a simple sentence. An independent clause contains a subject and a predicate and makes sense with another word(s).

Independent clauses can be joined by using a semicolon or by using a comma followed by a coordinating conjunction (and, but, for, or, nor, so, yet)

Examples

In the following example sentence, independent clauses are in italic, and conjunctions are in bold. Single independent clauses:

• I have enough money to buy an ice cream cone.
• My favourite flavour is chocolate.

Multiple independent clauses:

• I have enough money to buy an ice cream cone**;** my favourite flavour is chocolate.
• I have enough money to buy an ice cream cone, so let's go to the shop.

Dependent Clause

A dependent clause is a clause that provides a sentence element with additional information, but which cannot stand alone as a sentence. A dependent clause can either modify an adjacent clause or serve as a component of an independent clause. Some grammarians use the term subordinate clause to refer only to adverbial dependent clauses.

The different types of dependent clauses include content clauses (noun clauses), relative (adjectival) clauses, and adverbial clauses.

In Indo-European languages, a dependent clause usually begins with a dependent word. One kind of dependent word is a subordinating conjunction. Subordinating conjunctions are used to begin dependent clauses known as adverbial clauses, which serve as adverbs.

In the following examples, the adverbial clauses are bold and the subordinating conjunctions are italicized:

• Wherever she goes, she leaves her luggage (The adverbial clause wherever she goes modifies the verb leaves.)
• Bob enjoyed the movie more than I did. (The adverbial clause than I did modifies the adverb more.)

A subordinating conjunction can also introduce a noun clause:

• I know that he likes me. (The noun clause that he likes me serves as the object of the main-clause verb know.)

Another type of dependent word is the relative pronoun. Relative pronouns begin dependent clauses known as relative clauses; these are adjective clauses, because they modify nouns. In the following example, the relative clause is bold and the relative pronoun is italicized:

• The only one of the seven dwarfs who does not have a beard is Dopey. (The adjective clause who does not have a beard describes the pronoun one.)

A relative adverb plays the part of an adverb in a relative clause, as in

• That is the reason why I came. (The relative clause why I came describes the noun reason, and within the relative clause the adverb why modifies the verb came.)
• That is the place where he lives. (The relative clause where he lives describes the noun place, and within the relative clause the adverb where modifies the verb lives.)

An interrogative word can serve as an adverb in a noun clause, as in

• No one understands why you need experience. (The noun clause why you need experience functions as the direct object of the main-clause verb "understands", and within the noun clause why serves as an adverb modifying need.)

Complex Sentence

A complex sentence has one or more dependent clauses (also called subordinate clauses). Since a dependent clause cannot stand on its own as a sentence, complex sentences must also have at least one independent clause. In short, a sentence with one or more dependent clauses and at least one independent clause is a complex sentence.

A sentence with two or more independent clauses plus one or more dependent clauses is called compound-complex or complex-compound.

In addition to a subject and a verb, dependent clauses contain a subordinating conjunction or similar word. There are a large number of subordinating conjunctions in English. Some of these give the clause an adverbial function, specifying time, place, or manner. Such clauses are called adverbial clauses.

When I stepped out into the bright sunlight, from the darkness of the movie house, I had only two things on my mind. (S. E. Hinton, The Outsiders))
This complex sentence contains an adverbial clause, When I stepped out into the bright sunlight from the darkness of the movie house. The adverbial clause describes when the action of the main clause, I had only two things on my mind, took place. A relative clause is a dependent clause that modifies a noun or noun phrase in the independent clause. In other words, the relative clause functions similar to an adjective.

• Let him who has been deceived complain. (Miguel de Cervantes, Don Quixote)
• You, who have never known your family, see them standing around you. (J.K. Rowling, Harry Potter and the Sorcerer's Stone)

A noun clause is a dependent clause that functions like a noun.

In the first example, the restrictive relative clause who has been deceived specifies or defines the meaning of him in the independent clause, Let him complain.

In the second example, the non-restrictive relative clause who have never known your family describes you in the independent clause, You see them standing around you.

A noun clause may function as the subject of a clause, or as a predicate nominative or an object.
What she had realised was that love was that moment when your heart was about to burst. (Stieg Larsson, The Girl with the Dragon Tattoo)
In this sentence the independent clause contains two noun clauses.
The noun clause What she had realized serves as the subject of the verb was, and that love was that moment serves as complement. The sentence also contains a relative clause, when your heart was about to burst.

Sentence

A simple sentence consists of only one clause.
A compound sentence consists of two or more independent clauses.
A complex sentence has at least one independent clause plus at least one dependent clause.
A set of words with no independent clause may be an incomplete sentence, also called a sentence fragment.
A sentence consisting of at least one dependent clause and at least two independent clauses may be called a complex-compound sentence or compound-complex sentence.

1. I like trains.
2. I don't know how to bake, so I buy my bread already made.
3. I enjoyed the apple pie that you bought for me.
4. The dog lived in the garden, but the cat, who was smarter, lived inside the house.
5. What an idiot.

Sentence 1 is an example of a simple sentence.
Sentence 2 is compound because "so" is considereda coordinating conjunction in English, and sentence 3 is complex.
Sentence 4 is compound-complex (also known as complex-compound). Example 5 is a sentence fragment.

The simple sentence in example 1 contains one clause.
Example 2 has two clauses (I don't know how to bake and I buy my bread already made), combined into a single sentence with the coordinating conjunction so.
In example 3, I enjoyed the apple pie is an independent clause, and that you bought for me is a dependent clause; the sentence is thus complex.
In sentence 4, The dog lived in the garden and the cat lived inside the house are both independent clauses; who was smarter is a dependent clause.
Example 5 features a noun phrase but no verb. It is not a grammatically complete clause.

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.