Englishfor English speakers
the
Determiner
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Used, instead of a, to reference something specific, already known to exist.
Compare "I read a book." and "I read the book."
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Used with a stress, to show that the word following is special.
Are you the John Smith that I went to school with?
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Used with an adjective that acts like a noun to mean all of the people concerned
The poor are always with us.
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Used with superlatives forms of adjectives and adverbs.
You are the best.
next
Adjective
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The next thing is the one after this one.
I saw her again the next day.
The advances in technology will be amazing in the next decade or so.
When this is completed, the next step will be to edit everything carefully.
She plans to leave the company in the next two years.
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The next place is the one beside, or on the other side of this one.
No, this is number 12, number 14 is the next house.
Be quiet, the children are sleeping in the next room.
next
Adverb
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After something in order.
Next, we have the 6:00 news.
—
The time after this one.
The woman was next seen in the office 4 days later.
It was performed next the following year.
next
Preposition
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Beside something
She stood next to the window.
next
Determiner
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Next week, month, year, etc. is the one that follows this one.
I'll see you again next week.
but
Coordinator
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You use but to join two ideas and show that they are not the same.
I would take you there, but I do not have my car.
The changes were small but important.
"Do you speak French?" "No, but I speak Spanish."
It says this not in words but in pictures.
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You use but to change the topic.
I understand. And I'm sorry. But there is nothing I can do about it now.
And that's important, but another thing that has changed is the location.
but
Preposition
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except
He ate everything but the meat.
Any day but tomorrow would be fine.
I forgot my bag. I guess there's nothing to do but go back.
but
Adverb
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only
There is but one sun and one earth to live on.
one
Determinative
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(ordinal first) The number 1.
We have one nose and one mouth.
one
Noun
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The number 1.
One is the smallest whole number.
one
Pronoun
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One is a singular pronoun which means "someone" or "people". It is used more often in formal writing.
It is easy to see the difference if one looks closely enough.