April´s fool´s day

April Fool

1. A trick played on someone on April Fools' Day, or the person who is tricked
2. Said on April Fools' Day when you have tricked someone

April Fool's Day

Also Called All Fool's Day. It is on the first of April every year. People can play tricks, practical jokes and hoaxes on each other on this day.

Fool

A person who behaves in a silly way without thinking or someone who doesn't understand what's happening around him/her

Hoax

A plan to deceive someone, such as telling the police there is a bomb somewhere when there is not one, or a trick:

The bomb threat turned out to be a hoax

Gullible

easily deceived or tricked, and too willing to believe everything that other people say:

There are any number of miracle cures on the market for people gullible enough to buy them

Play a joke (on someone)

(Also play a trick on someone.) Do something funny (an amusing trick) that is done in order to make people laugh and that another person doesn't suspect at first.

Practical joke

A playful trick that usually puts the receiver in an embarrassing position.

Prank

A trick that is intended to be amusing but not to cause harm or damage:

When I was at school we were always playing pranks on our teachers.
I've had enough of your childish pranks

Prankster

Someone who performs pranks on people

Spoof story

It is a story that's not true, presented as though it were real.

reading: http://www.myenglishpages.com/site_php_files/reading-april-fool-day.php
exercise: http://www.myenglishpages.com/site_php_files/vocabulary-exercise-april-fool-day.php