Function of conjunctions in sentences

1. The Concept of Conjunctions

Summary: Conjunctions in English are words that connect two simple sentences into one compound sentence. Each simple sentence in a compound sentence is called a clause. Each conjunction has a specific meaning, expressing the relationship between the sentences it connects. Conjunctions in English are words that connect two simple sentences into one compound sentence. Each simple sentence in a compound sentence is called a clause.

Conjunctions help us express complex ideas by combining simple sentences. Each conjunction carries a different meaning, reflecting the relationship between the sentences it connects.

Examples:

• I like the smell of coffee, but I don't like drinking coffee.
• I don't like drinking coffee, so I ordered some tea.

I don't like drinking coffee, so I ordered some tea.

- But according to the definition above, conjunctions connect two sentences. So what about these cases?

• I love tea and milk.
• Tim and I are studying English.

- The conjunction and in the above sentences does not connect two sentences but connects two words (connecting tea with milk; connecting Tim with I). We can understand that conjunctions can connect two nouns, or we can understand it as follows:

• I love tea and milk.

→ Since both sentences share the same subject I and the same verb love, the sentence can omit one instance of I love to make it more concise.

• Tim and I are studying English. = Tim is studying English and I am studying English.

→ Since both sentences share the same action to be studying English, the sentence can omit one instance of to be studying English to make it more concise.

- Thus, we can still understand that the primary function of conjunctions is to connect two simple sentences into one compound sentence!

I love tea and milk. = I love tea and I love milk.

2. Three Ways to Separate Two Sentences in English

Summary: In English, two sentences can only be separated in one of three ways: Full stop (period) Semicolon Conjunction

In Vietnamese, we can separate two sentences quite flexibly with a period or a comma, for example:

• My mother often takes me to the park. Every time we go there, I feel very happy.
  

However, in English, two sentences can only be separated by a period, a semicolon, or a conjunction.

• My mother often takes me to the park. Every time we go there, I feel very happy.
• My mother often takes me to the park; every time we go there, I feel very happy.
• My mother often takes me to the park, and every time we go there, I feel very happy.

My mother often takes me to the park, and every time we go there, I feel very happy.

We must be extremely careful that in English, a comma cannot be used to connect two sentences.

• GRAMMAR ERROR: My mother often takes me to the park, every time we go there, I feel very happy.

3. Distinguishing Conjunctions and Prepositions

Summary: The difference between conjunctions and prepositions: A clause cannot follow a preposition. A clause can follow a conjunction.

Conjunctions connect two simple sentences into one compound sentence, so a clause (a complete sentence with a subject and conjugated verb) must follow a conjunction. This is the clearest difference between conjunctions and prepositions:

• A clause cannot follow a preposition.

• A clause can follow a conjunction.

Examples:

• I couldn't go out because of the rain.

→ I couldn’t go out because of the rain. → Since the rain is not a clause (a complete sentence) but only a noun phrase, a preposition because of must be used here.

• I couldn't go out because it was raining.

→ I couldn’t go out because it was raining. → Since it was raining is a clause (a complete sentence), a preposition like because of cannot be used here; instead, the conjunction because is required.

4. Distinguishing Conjunctions and Adverbs

Summary: The difference between conjunctions and adverbs: A conjunction must appear at the beginning of one of the two clauses. An adverb does not necessarily have to appear at the beginning of a sentence.

Let’s look at these two sentences:

• I came to visit Mary. However, she was not home.
• I came to visit Mary, but she was not home.

At first glance, however seems like a conjunction because it connects two sentences, but in reality, however is an adverb, not a conjunction, for two reasons:

+ First, the two sentences are still separated by a punctuation mark (a period), not combined into one sentence.

+ Second, however can move to other positions in the second sentence, not necessarily at the beginning:

• I came to visit Mary. However, she was not home. = I came to visit Mary. She was not home, however.
• I came to visit Mary, but she was not home.

This is the clearest difference between conjunctions and adverbs:

• A conjunction must appear at the beginning of one of the two clauses.
• An adverb does not necessarily have to appear at the beginning of a sentence.

5. Types of Conjunctions

Conjunctions in English can be divided into the following types. You can click on the link for each type to learn more details about it.

Type of Conjunction	Conjunctions	Examples
Coordinating Conjunctions	Seven words: and, or, nor, but, yet, for, so	I love tea and milk.
Correlative Conjunctions	Some common correlative conjunctions: both... and... either... or... neither... nor... not only... but also...	Not only did she forget my birthday, but she also didn’t even apologize for forgetting it.
Subordinating Conjunctions	Some common subordinating conjunctions: before, after, when, while, until, although, because, since...	He is learning English because he wants to talk to people from all over the world.

6. Summary