Englishfor English speakers
a
Determinative
—
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
—
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.
case
Noun
—
A case is a container to hold something.
He opened the case and pulled out his violin.
—
A case is a matter for police or in court.
The judge did not accept his case.
—
A case is the form of a noun showing how it is used in a sentence.
The word "he" is in the subject or nominative case.
—
A case is a person of a certain kind.
That man is sure a hard case.
case
Verb
—
If a police officer cases a house, he or she watches it until something happens.
We were casing a house all night in Brooklyn.
off
Preposition
—
Away from somewhere or some time.
I got ready and by 7:00 I was off to school.
There's a nice restaurant just off the main road.
Bye, I'll be off now.
He was standing about 50m off.
Your birthday's only a few days off now.
—
If something is off it is not on.
She took the hat off his head.
Keep your feet off the desk, please.
—
Out of a vehicle such as a train, bus, etc.
As the train stopped, he jumped off and ran to her.
—
If something that uses energy is off, it is not working.
It was dark in the room because the light was off.
He turned the TV off and went to bed.
—
If you are off, you do not have to go to work or to school.
I work evenings, but I have my afternoons off.
—
made smaller by a certain amount
They've taken 30% off the price.
We cut off a few pieces.
—
If a plan, event, etc. is off, it will not happen.
Tonight's game is off because of the rain.
They've called off the meeting.
—
If you're off something, you don't like or want something you wanted before.
That article really put me off meat.
—
If you're off some medicine, you are not using it any more.
He's been off the pain killers for a few weeks.
off
Adjective
—
If food is off, it is not good to eat anymore.
off
Verb
—
If a person offs someone, they kill him or her.
I heard they offed Jimmy by drowning.