In English, a clause and a phrase are key components that make up longer sentences. To identify a clause, it is crucial to first understand the difference between the two. Once you grasp the basic concept, recognizing the different types of clauses becomes easier. This foundation will help you construct longer sentences with correct grammar, without getting confused by more complex English clauses.
Steps
What is a Clause?

A clause is a group of words with two parts. The first part is the subject: the word referring to the person or thing performing an action. The second part is the verb in its conjugated form: this word indicates the action the subject is performing.
- "They run" is a clause with the subject (they) and the action (run).
- "They run to the store" is also a clause. The "action" in this example consists of more words, but it still conveys the same meaning.
- "My dog is a good boy" is also a clause. The word "is" (or "are") is considered the "action".
Cụm từ là gì?

Cụm từ không có đủ thông tin để trở thành một mệnh đề. Mệnh đề luôn cho chúng ta biết ai (hoặc cái gì đó) đang làm gì. Nếu một nhóm gồm các từ không thể hiện được chức năng này, chứng tỏ đây là một cụm từ. Cụm từ chỉ cho chúng ta biết một thông tin.
- Ví dụ: câu "After work, my dad cooks dinner" có một cụm từ và một mệnh đề.
- Mệnh đề là "my dad cooks dinner", trong đó bao gồm chủ từ ("my dad") và hành động ("cooks dinner").
- Cụm từ là "After work". Cụm từ này không cho chúng ta biết về chủ từ hay hành động nào.
Phương pháp kiểm tra bằng cách loại bỏ tính từ

Bạn có thể loại bỏ các tính từ nhằm xác định nội dung nào đó có phải là mệnh đề hay không. Tính từ và trạng từ là những thành phần phụ bổ sung để câu rõ nghĩa hoặc hay hơn chứ không bao gồm ý chính. Nếu bài tập về nhà yêu cầu như sau: "Is this a phrase or a clause?" (Đây là cụm từ hay mệnh đề?), hãy thử gạch bỏ các tính từ và trạng từ. Cách này sẽ giúp bạn thấy được thành phần nào là quan trọng.
- Ví dụ 1: "The happy young students run quickly to the large candy store." Sau khi gạch đi các tính từ và trạng từ, câu sẽ trở thành "the students run to the candy store." Lúc này, bạn vẫn biết được ai đang làm gì, vì thế đây là một mệnh đề.
- Ví dụ 2: "Slowly climbing the big staircase." Tương tự, hãy gạch đi các tính từ và trạng từ. Lúc này, bạn có "climbing the staircase". Chúng ta không thể biết được ai đang leo cầu thang, vì thế đây không thể là một mệnh đề mà là cụm từ.
Phương pháp kiểm tra "is it true that..."

Insert this phrase into the group of words and check if the sentence makes sense. If adding it results in a meaningful sentence, then the words form a clause. If not, it's likely a phrase. Here are some challenging examples to test your understanding:
- My friend holding the pizza → "Is it true that my friend holding the pizza?" This content is nonsensical, so it is a phrase.
- People who walk fast → "Is it true that people who walk fast?" This is meaningless, so it's also a phrase.
- Apply the test to the following example: "people who walk fast are annoying." The result is "Is it true that people who walk fast are annoying?" which forms a normal sentence with a subject ("people who walk fast") and a predicate ("are annoying").
Independent Clause

An independent clause can stand alone as a complete sentence with a subject ("who" or "what" the sentence is about) and a predicate (the action or main part of the sentence). Most clauses are independent clauses.
- For example: The tree grew very tall is an independent clause. This is a complete sentence.
- Consider the sentence: "While eating breakfast, I read a comic book." The main part of the sentence is "I read a comic book." This can stand alone as a complete sentence, so "I read a comic book" is an independent clause.
Combining Independent Clauses

Words like "and" or "but" are commonly used to connect two independent clauses, as a sentence can contain multiple clauses. To identify clauses in a long sentence, look for "coordinating conjunctions" (also known as "linking words" or "connectors"). Coordinating conjunctions like for, and, nor, but, or, yet, and so link two or more independent clauses. You can remember these words by the acronym "f-a-n-b-o-y-s".
- Example: Try identifying the two clauses in the sentence "The cloud is moving fast, but I can run faster".
- "But" is the coordinating conjunction connecting the two independent clauses in the sentence.
- The content before "but" is one independent clause: "The cloud is moving fast".
- The content after "but" is another independent clause: "I can run faster".
Dependent Clause

A dependent clause is a clause that cannot stand on its own to form a meaningful sentence. Like all clauses, a dependent clause includes a subject ("who" or "what" the sentence is about) and an action, but it cannot function as a complete sentence by itself. Dependent clauses are introduced by words like because, although, if, or when. These words link the dependent clause to another part of the sentence.
- For instance, "Because I baked a second cake" is a dependent clause. It has a subject ("I") and an action ("baked a second cake"), but it doesn't form a complete sentence because there is an unresolved question: Because what?
- "Because I baked a second cake, everyone had enough to eat" is a complete sentence containing two clauses. "Because I baked a second cake" is the dependent clause, while "everyone had enough to eat" is an independent clause.
Relative Clause

Words like "who" or "which" begin a relative clause. This is a type of dependent clause that cannot stand alone as a complete sentence. Instead, the relative clause provides additional information about a noun in the sentence.
- In the sentence "A woman who knows about spiders gave a presentation," the word "who" introduces a relative clause.
- "Who knows about spiders" is the relative clause. This part further explains the woman in the sentence. It cannot stand alone as a complete sentence.
- "Who" is the subject and "knows about spiders" is the action ("verb in the conjugated form").
- Relative clauses may begin with relative pronouns (who, whom, whose, that, which) or relative adverbs (when, where, why).
Relative Clause Without the Word "Who"

Sometimes the word "who" is omitted from a relative clause. This can make it harder to recognize the relative clause. Here's how you can identify a relative clause when "who" is missing:
- The relative clause will follow a noun. For example: "the bear you warned me about ate my tent". In this sentence, the relative clause "you warned me about" follows the noun "bear".
- You can omit the relative clause, and the sentence still makes sense. In the example above, even after removing "you warned me about", the remaining part is still a complete sentence: "The bear ate my tent".
- You can add the word "who" back. In this case, you could use "that": "The bear that you warned me about ate my tent".
Complex Clauses with the "-ing" Suffix

Words with the "-ing" suffix cannot function as the main verb. Every clause has a verb, so start by identifying the main verb. However, when we add "-ing" to a verb, it turns into an adjective that describes a noun.
- For example, identify the clause in the sentence "The rushing river flooded the field."
- First, it's easy to spot two verbs: "rushing" and "flooded".
- But in this case, "rushing" is not functioning as a verb but as an adjective. Therefore, it cannot be the main verb of the clause.
- So, the entire sentence contains just one clause.
- A more complex example: Identify the clause in the sentence "The bear living in the woods drinks from the stream running down the mountain."
- In this case, both "living" and "running" are not verbs. These words begin the phrases "living in the woods" and "running down the mountain". The only verb here is "drinks", so the entire sentence is one clause.
Complex Clauses with the "-ing" Suffix as Nouns

Words ending in "-ing" can function as nouns. This might seem odd and complicated to English learners (verbs acting as nouns?), but for native speakers, it's quite normal. In short, don't worry too much about the grammar.
- For example: "Sleeping is my favorite thing to do" is a clause.
- The subject of this clause is "sleeping".
- It’s easier to notice that "sleeping" is in the position where the subject usually is, right before the verb: "Sleeping is" instead of "The tree is".
Complex Clauses with Words Ending in "-ed" or "-en"

Words ending in "-ed" or "-en" can function as either verbs or adjectives. When they are verbs, they describe actions that occurred recently. When they act as adjectives, they describe the inherent state of a noun as it was originally:
- "A cracked window let the cold wind through" is a clause with the main verb "let". The word "cracked" is not functioning as a verb here, so there's no second clause. This adjective describes the condition of the window, which was already cracked.
- "A window cracked and a dog howled" is a sentence with two independent clauses: "a window cracked" and "a dog howled". In these cases, the word ending in "-ed" acts as a verb showing that an event has just occurred.
- If a word with the "-ed" suffix appears before the subject, it's usually an adjective, not a verb.
- If a word with the "-ed" suffix appears after the subject, it could be either an adjective or a verb. For example, "A window cracked by a hailstone" is a phrase, not a clause. This phrase describes an event that has already happened to the window (in a passive form), not an action the window is currently performing.
Infinitive Clauses

Verbs in the "to ___" form are not the main verbs. These are called "infinitive verbs". A group of words containing an infinitive verb and no other main verb forms a phrase, not a clause. There are many ways to use infinitives, but here's one of the most common:
- I want to eat is a clause. In this case, "want" is the main verb, and "to eat" is just part of the full verb ("want to eat"). Since "to eat" isn't the main verb, it can't form a new clause.
Advice
- A relative clause is also known as a "descriptive clause". This type of clause describes a noun by using an adjective.
- Some teachers and textbooks refer to dependent clauses as "subordinate clauses". These terms are interchangeable.
Warning
- In casual conversation, we often speak in phrases. For example: "You first?" "No, after you." However, in grammar, these are incomplete sentences. They are better described as phrases, not clauses.
- The "is it true that" test can be applied to all independent clauses, but it does not work for dependent clauses.
