Pronunciation: /wʌn/
noun refers to the number 1 or a single person or thing
A1 I have one book.
A2 She bought one ticket for the concert.
B1 I need to buy a new one.
B2 The red one is my favorite.
C1 I have only one chance to make it right.
C2 She is the one I've been looking for all my life.
adjective used to refer to a single person or thing, or to emphasize that there is only one
A1 I have one pencil in my bag.
A2 She only needs one more book to complete her collection.
B1 I bought one ticket for the concert.
B2 There is only one solution to this problem.
C1 Having just one option makes decision-making easier.
C2 The CEO is considered one of the most influential leaders in the industry.
pronoun used to refer to a person or thing previously mentioned or easily identified
A1 I have one brother.
A2 Can I have one more cookie, please?
B1 She is the one who always arrives early.
B2 One must always be prepared for unexpected challenges in life.
C1 As one gets older, they tend to appreciate the simple things in life more.
C2 One should never underestimate the power of kindness in making a difference in the world.
formal In this experiment, one must carefully follow the instructions to achieve accurate results.
informal If you're looking for a good restaurant, that one over there is really popular.
slang I can't believe that one got away with cheating on the test.
figurative Sometimes in life, we have to let go of the old to make room for the new, like shedding one's skin.
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