Grammar · Free lesson
A or the? Does the listener know which one?
A notebook introduces one item. The notebook points to a particular one. Practice how that changes a short exchange.
Professor Scott MendozaThe short answer
Use a or an to introduce an unspecified member of a group. Use the when the listener can identify the one you mean, including from something already mentioned.
Ask whether the listener can identify it.
This lesson uses singular countable nouns: things you can count as one notebook or two notebooks. Use a or an when introducing an unspecified member of a group. Use the when the listener can identify the particular item you mean. Mentioning an item earlier is one way to identify it; shared knowledge or the situation can also make it clear.
Introduce it. Refer to it again.
I bought a notebook.
The notebook has a green cover.
In our kitchen with one fridge: Please close the fridge.
The second sentence points back to the notebook already introduced. In the kitchen example, the situation identifies the fridge even though you have not mentioned it before.
Choose an article for a specific item
Check the noun
Here, you are talking about one countable item.
Check what is shared
Can the listener tell which item you mean from the conversation or situation?
Choose the article
Introduce an unspecified item with a/an. Refer to an identifiable item with the.
Try it now
Check what you’ve learned.
Read all answers and explanations
Introduce an unspecified notebook: I bought ___ notebook.
aThe listener has not been told which notebook you mean.
Refer to that same notebook: ___ notebook has a green cover.
TheThe first sentence identified this particular notebook.
You and a friend are in your kitchen with one fridge. Ask them to close it.
Please close the fridge.Shared context identifies which fridge you mean.
Build it yourself
Ask for the notebook you mean.
You told a friend you brought a notebook earlier. Ask for the particular notebook you left beside their laptop. Begin with “Please pass me.”
Choose every piece in order. The detail after notebook identifies which one you mean. Select a piece again to move it back.
Your request
0 of 4 piecesYour chosen pieces will appear here.
See a model answer
Please pass me the notebook I left beside your laptop.
“The notebook I left beside your laptop” identifies a particular notebook. The detail helps your friend know which one to pass.
A little more clarity
Common questions
A few useful details before you move on.
Can I use “the” the first time I mention something?
Yes. Earlier mention is not the only way to identify an item. The listener may already know which one you mean from your shared situation.
In a room with one open window: “Could you close the window?”
Why is it “an hour” but “a university”?
The sound after the article decides. Hour starts with a vowel sound because its h is silent. University starts with a consonant sound, like the beginning of you.
“We waited an hour.” / “She works at a university.”
Take it into your day
Describe one item you bought or found. Introduce it with a/an, then use the to add a detail about the same item.
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