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".
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In some schools, an A is a very high grade.
Ron got an A on his earth science test.
lost
Adjective
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If you are lost you do not know where you are. You might not know how to get home.
I was lost in the woods for a week.
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If something is lost you do not know where it is.
My phone is lost.
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If something is lost it is gone. It might not exist any more.
All my hope is lost.
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If something is lost it has failed.
Trying to reach her is a lost cause.
cause
Noun
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A cause is what leads to something happening.
The cause of the fire was lightning.
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A cause is a goal, aim or principle that people support or fight for.
He is fighting for a just cause.
cause
Verb
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To cause something is to make it happen.
His careless driving caused the car accident.