Englishfor English speakers
a
Determinative
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A is used when the following word could be any of a certain type.
Compare "A book I saw on the shelf" and "The book I gave you yesterday".
a
Noun
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A is the first letter of the alphabet.
The letter "a" comes before "b".
—
In some schools, an A is a very high grade.
Ron got an A on his earth science test.
AD
Abbreviation
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AD is short for the Latin words anno Domini, which means in the year of our Lord. You use AD to refer to a date after the year in which Jesus Christ is believed to have been born.
The Romans started building the Colosseum in 70 AD.
ad
Noun
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A short way of saying advertisement.
I saw an ad in the newspaper for a job at the factory.
minimum
Noun
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The minimum is the lowest number, size, amount, etc. that exists, that is allowed, or that is possible.
Try to keep drinking to a minimum at school.
A minimum of three workers is needed to do the job.