IRREGULAR PLURAL FORM

There are tens of words that differ from singular to plural.
Take a look at a short list of them:

CHILD - CHILDREN
MAN - MEN
PERSON - PEOPLE
FOOT - FEET

The ones above are constantly drilled by teachers, right?
What about the following ones?

STAFF - STAFF
BACTERIUM - BACTERIA
DEER - DEER
AIRCRAFT - AIRCRAFT
APPENDIX - APPENDICES
BOOTH - BOOTHS

Attention to verb conjugation when using the words above:

The staff were really helpful.
The bacteria have spread to other parts of the body.
Both booths are broken.


Best wishes,
André

LANGUAGE IMPROVEMENT

One good piece of advice for you to improve your English is replace the words you already know for those you still need practice with.
Take a look at the exmaples below:

I have too much work = I have INSURMOUNTABLE work
Let's get started = Let's get THE BALL ROLLING 
I will give him some info = I will PROVIDE him WITH some info
She got hurt = She got INJURED
It was a delicious cake = It was a SCRUMPTIOUS cake

Watch out for opportunities to do it!

Best wishes,
André

UNCOUNTABLE NOUNS

 

Pay attention to the uncountable nouns below:

 

INFORMATION

ADVICE

EQUIPMENT

WORK

PAPER

MAIL

KNOWLEDGE

HELP

TROUBLE

STUFF

CARGO

FURNITURE

LAND

NEWS

LUGGAGE / BAGGAGE

 

You are not supposed to conjugate verb TO BE in the plural form with these nouns!