Common mistake: “A pen is a thing who you use to write.” — Correct: “A pen is a thing that you use to write.”
We use 'which' or 'that' (not 'who') to define a thing by its use: 'a thing that you use to + verb'.
a thing that you use to + action
Object
Definition
A pen
is a thing that you use to write
A computer
is a thing that you use to work
A ruler
is a thing that you use to measure
A dictionary
is a thing that you use to check words
Pen — write
Pencil — draw and write
Notebook — write notes
Computer — work and study
Laptop — work anywhere
Keyboard — type words
Mouse — click and move
Ruler — measure and draw lines
Eraser — erase mistakes
Calculator — do calculations
Dictionary — check words
Backpack — carry your things
Printer — print documents
Marker — write on the board
A pen is a thing that you use to write.
A computer is a thing which you use to work and study.
A ruler is not a thing that you use to write.
A printer isn't a thing you use to cook.
What do you call a thing that you use to write?
Is a dictionary a thing you use to check words?
Is a pen a thing you use to write? Yes, it is.
Is a backpack a thing you use to cook? No, it isn't.
Practice
A pen is a thing ___ you use to write. (who, that, where)
We use 'which' or 'that' for things, not 'who'.
A pen is a thing that you use to ___.
A dictionary is a thing that you use to check ___.
A printer is a thing that you use to ___ documents.
A backpack is a thing that you use to ___ your books.
Find the mistake: A computer is a thing who you use to work.
A notebook. You use it to write notes. — Join them with 'that'.
What do you call a thing that you use to write?
Listening
Kenji: Last round! A thing that you use to write.
Ben: A pen!
Kenji: Correct. A thing that you use to check words?
Ben: A dictionary!
Kenji: And a thing that you use to carry your books?
Ben: A backpack! I win the game.
Reading
On Sofía's desk there are many useful things. A pen is a thing that she uses to write, and a notebook is a thing that she uses to take notes. Her computer is a thing that she uses to work, and a dictionary is a thing that she uses to check English words. 'What is the most important thing on your desk?' asks Kenji. 'My coffee!' Sofía laughs. 'It's a thing that I use to wake up!'
A pen is a thing that Sofía uses to write.
Sofía uses a dictionary to cook.
Sofía jokes that coffee is a thing she uses to wake up.