Take a moment. Without looking anything up, write or say what you remember about relative clauses. What do you know about "who," "which," and "that"?
Native speakers use relative clauses constantly—but they use them in ways you might not have learned yet. Some clauses give essential information. Some add extra details. Some use "whose" or "where" to sound more natural. Today you'll learn the patterns that make your English flow better.
Some relative clauses add extra information, not essential information. We use commas to show this.
Essential: "The teacher who spoke today was brilliant."
→ Which teacher? The one who spoke today.
Extra info: "My teacher, who spoke today, was brilliant."
→ You know who she is. By the way, she spoke today.
In some sentences, you can leave out "who," "which," or "that" and the sentence still works.
Full: "The person who I met yesterday was kind."
Omitted: "The person I met yesterday was kind."
Full: "The article that you recommended is excellent."
Omitted: "The article you recommended is excellent."
Whose = belonging to (shows possession)
Example: "The student whose project won the award is in my class."
Where = in/at which place
Example: "The café where we met is closing down."
When = at which time
Example: "The day when you arrived was unforgettable."
I'll give you a situation. You decide which pattern to use and complete the sentence. Then we'll talk about why it works.
Situation: You have many friends. One of them is a doctor. You want to tell someone about this friend.
Complete the sentence (use commas only if needed):
"My friend is a doctor."
Option A: who I've known for years (no commas) / Option B: , who I've known for years, (with commas)
Situation: You're talking about a book you just finished reading.
Rewrite this sentence in a shorter way (omitting the relative pronoun):
"The book that I finished yesterday was amazing."
Situation: You want to describe a special moment during your holiday.
Complete using "where" or "when":
"That summer morning we first met was magical."
Now you're in control. Below are three situations. For each one, create a sentence using the pattern indicated. Speak your answer out loud, then type or write it down.
Situation: You want to give extra information about your English teacher. Create a sentence that adds detail without defining which teacher (you've already mentioned her).
Pattern: "My English teacher, who [extra detail], [what about her?]"
Situation: You want to describe a movie you watched. Make the sentence shorter by leaving out the relative pronoun.
Pattern: "The film [you/I] [action] was [opinion]"
Situation: Describe a meaningful place or moment in your life.
Pattern: "The [place/time] where/when [something happened] [result or meaning]"
Below are seven sentences. Some have clear relative clauses. Some have omitted them. Some use where or when. For each one, explain what pattern it's using—then try to rewrite it in a different way.
Original: "The restaurant we discovered was hidden down a quiet street."
Question: What relative pronoun was omitted? Rewrite it with the pronoun included.
Original: "My colleague, who started last month, already knows everyone."
Question: Why does this have commas? What would change if we removed them?
Original: "The year when everything changed was 2020."
Question: How would you rewrite this using "in which" instead of "when"?
Learning is stronger when you explain it to yourself. Answer these questions in your own words—no right or wrong, just your understanding.
Think about the difference between these:
How would you explain to someone why the commas change the meaning?
Why do you think we can omit "that" in "The book I read" but not in "The book that made me cry"?
Both of these are correct:
Which one sounds more natural to you? Why do you think that is?
At the start, we said you'd be able to use three patterns of relative clauses. Let's check in.
Create a sentence about someone you know. Add extra information using a non-defining clause (with commas).
Think of something you bought, read, or watched recently. Describe it using a relative clause—then omit the pronoun.
Describe a place or time that's important to you. Use where or when in your sentence.
Reflect on this lesson. What activity or explanation helped you understand relative clauses better? Was it the visual examples? The co-construction? The practice?
You now have three powerful patterns to add to your English toolkit. The more you use these—especially the commas in non-defining clauses and the natural "where/when"—the more natural your English will sound.