Chapter: Uses of Conjunctions and That-Clauses
Welcome to your study notes on conjunctions and that-clauses! Imagine building a house: bricks alone cannot stay together without mortar. In English, words and simple sentences are your building blocks, and conjunctions are the mortar that connects them. Whether you want to share an opinion in a debate, explain a reason in a presentation, or write a coherent paragraph, using conjunctions and clauses correctly is the key to expressing yourself clearly and logically.
Don't worry if long English sentences look intimidating at first. Once you know how conjunctions piece ideas together, you can easily break down any complex sentence into simple, understandable parts.
Note: For connecting ideas using relative words or prepositions, please refer to our related chapters: "Uses of relative pronouns", "Uses of relative adverbs", and "Uses of prepositions".
---1. The Two Big Families of Conjunctions
A conjunction is a connecting word. There are two main types you need to know:
1. Coordinating conjunctions: Connect words, phrases, or clauses that are grammatically equal (balanced).
2. Subordinating conjunctions: Connect a main clause (the independent idea) to a dependent clause (which adds extra information like time, reason, or condition).
A. Coordinating Conjunctions (Connecting Equals)
Coordinating conjunctions link two elements of the exact same type — word to word, phrase to phrase, or independent sentence to independent sentence.
The most common coordinating conjunctions are and (addition), but (contrast), or (choice), and so (result).
Examples:
• Word + Word: Do you prefer tea or coffee?
• Clause + Clause: Ken studied hard, but the test was challenging.
• Cause and Result: It began to rain, so we stayed indoors.
Punctuation Tip (The Comma):
When you connect two complete sentences with a coordinating conjunction, place a comma (,) before the conjunction (e.g., Sentence A, and Sentence B).
B. Paired Conjunctions (Correlative Conjunctions)
Some coordinating conjunctions work in pairs to add emphasis and rhythm to your speech and writing:
• both A and B = both A and B (e.g., She speaks both English and Japanese.)
• either A or B = one of the two (e.g., You can have either tea or coffee.)
• neither A nor B = not A and not B (e.g., He has neither the time nor the money for a trip.)
• not only A but also B = not just A, but B as well (e.g., The project requires not only creativity but also teamwork.)
Key Takeaway: Coordinating conjunctions balance equal parts. Make sure what comes after the first conjunction matches the grammatical form of what comes after the second.
---2. Subordinating Conjunctions: Adverb Clauses
A subordinating conjunction introduces a dependent clause (a mini-sentence with a subject and a verb that cannot stand alone as a complete sentence). Together, they tell us when, why, under what condition, or in spite of what the main action happens.
A. Conjunctions of Time
These tell your listener or reader when something takes place:
• when: at that time (Call me when you arrive.)
• while: during the time that (I listened to music while I was cooking.)
• before / after: earlier than / later than (Wash your hands before you eat.)
• until / till: up to the point in time (We waited until the rain stopped.)
• as soon as: immediately after (I will email you as soon as I get the results.)
B. Conjunctions of Reason and Cause
Use these when explaining your reasons in discussions, presentations, or essays:
• because: focuses strongly on the reason (He stayed home because he felt ill.)
• since / as: used when the listener already knows the reason or it is background information (Since we have extra time, let's review the vocabulary.)
C. Conjunctions of Condition
• if: provided that (We will go hiking if it is sunny tomorrow.)
• unless: except if / if not (We will be late unless we hurry. = if we do not hurry)
D. Conjunctions of Concession and Contrast
These show a surprising contrast or show that something happened despite an obstacle:
• although / though / even though: even if it is true that (Although the train was crowded, we found seats.)
• while: can also mean "whereas" to contrast two facts (Some students enjoy science, while others prefer art.)
Comma Rule for Subordinating Conjunctions
When the dependent clause comes first, put a comma after it:
• Because it was raining, we stayed inside. (Comma needed)
When the main clause comes first, you usually do not need a comma:
• We stayed inside because it was raining. (No comma needed)
Key Takeaway: Subordinating conjunctions create adverbial clauses that answer questions like "Why?", "When?", or "Under what condition?". Remember the comma when starting a sentence with one of these clauses!
---3. That-Clauses: Turning Sentences into Information Units
The word that can act as a conjunction that introduces a noun clause. Think of a noun clause as an entire sentence packed neatly into a single box (a noun). You can place this box anywhere a noun normally goes: as a subject, an object, or a complement.
A. That-Clause as an Object (Reporting Thoughts, Feelings, and Facts)
This is the most common use in everyday conversations, speeches, and discussions. You pair a verb expressing thinking, speaking, or feeling with a that-clause to share information.
Common verbs used with that-clauses:
• think that: I think that solar energy is vital for the future.
• believe that: Many people believe that regular exercise reduces stress.
• know that: We know that clean water is essential for health.
• say / explain that: The teacher explained that the museum opens at nine.
• hope that: I hope that you enjoy your stay.
Did you know? In everyday spoken English and informal writing, the word that is very often omitted:
• I think that she is right. = I think she is right.
Both are completely correct!
B. That-Clause after Adjectives of Emotion or Certainty
You can use a that-clause after adjectives describing how someone feels or how certain someone is:
• I am glad that you could come today. (emotion)
• We were surprised that the team won the championship. (emotion)
• I am sure that everything will go smoothly. (certainty)
C. That-Clause with "It is ... that" (Dummy Subject)
Instead of putting a heavy clause at the beginning of a sentence, English prefers to start with It and put the that-clause at the end:
• It is true that learning a new language takes time.
• It is important that we listen to different opinions in a discussion.
D. That-Clause in Apposition (同格 - Explaining a Noun)
A that-clause can directly follow certain abstract nouns to explain their exact content:
Common nouns followed by that: fact, news, idea, hope, rumor, belief
• The fact that she solved the problem alone impressed everyone.
(The that-clause tells us exactly what the fact is: "she solved the problem alone".)
• The news that the event was canceled surprised us.
(The that-clause specifies what the news is.)
Watch Out: Apposition "that" vs. Relative Pronoun "that"
• Appositive that: The clause after that is complete on its own: The fact that [he won the prize] is true. (Subject, verb, and object are all present inside the clause).
• Relative that: The clause has a missing part (subject or object) because that replaces it: The news that [we heard yesterday] was shocking. (Here, heard is missing its object).
Key Takeaway: A that-clause turns an entire statement into a noun unit, allowing you to share ideas, report what others say, describe feelings, and explain the content of facts or news.
---4. Using Conjunctions for Logical Communication
When you take part in discussions, deliver presentations, or write structured paragraphs in senior high school, conjunctions guide your audience through your logic step by step.
A. Stating an Opinion and Giving Reasons
Use conjunctions to connect your claim with evidence:
• "In my opinion, we should support this plan because it helps our community."
• "Since public transportation reduces carbon emissions, more people should use it."
B. Presenting Two Sides of an Issue (Discussion & Debate)
Use contrast conjunctions to acknowledge an opposing viewpoint before stating your own:
• "Although online shopping is convenient, local stores provide personal customer service."
• "Electric cars produce less pollution, but their batteries require special disposal."
C. Connecting Ideas across Sentences (Punctuation Note)
In senior high school reading and writing, you will encounter punctuation marks like the semicolon (;) and the dash (—) alongside conjunctions:
• Semicolon (;): Connects two closely related independent clauses without a coordinating conjunction (e.g., The library was quiet; everyone was studying.).
• Dash (—): Adds an abrupt change in thought, summary, or extra emphasis (e.g., He had only one goal — to pass the exam.).
5. Common Mistakes to Avoid
Mistake 1: The "Because ... so ..." Double Conjunction
In Japanese, people often say "〜だから、…です" (Because A, therefore B). However, in English, you must only use one conjunction to connect two clauses.
• Incorrect: Because it was late, so I went to bed.
• Correct: Because it was late, I went to bed.
• Also correct: It was late, so I went to bed.
Mistake 2: The "Although ... but ..." Double Conjunction
Just like with "because ... so", do not use both although and but together in one sentence.
• Incorrect: Although he was tired, but he continued walking.
• Correct: Although he was tired, he continued walking.
Mistake 3: Writing an Incomplete Clause
A subordinating conjunction must be followed by a full clause with both a subject and a verb.
• Incorrect: I stayed home because the heavy rain.
• Correct: I stayed home because it rained heavily. (Or use the preposition: because of the heavy rain.)
Quick Review: Conjunction Checklist
Before speaking or handing in your writing, ask yourself:
✔ Did I connect two full sentences with and / but / or / so using a comma?
✔ Did I place a comma after an introductory When / If / Because / Although clause?
✔ Did I avoid combining Because and so (or Although and but) in the same sentence?
✔ Did I use a that-clause to clearly state what I think, believe, or report?