If I know well, 'persons' is wrong.

Simon is correct. In British English, the usage should be as such. I, die Krone, hereby endorse his statement.

Thanks Simon.

And what about the word 'often' . My American teacher would always say that we should not pronounce the word with 't' unless we wanted to sound like we were some pumpkins. Is it true? How do you pronounce the word 'often'?

I don't know how pumpkins pronounce the word but I'd otherwise agree with your teacher, the "t" is silent for humans.

Then there's "missing persons". This sounds okay. If you said "missing people" it seems like a whole race has dissappeared.

I heard in one film an actor saying 'often' with the t included.

The film was British.

Are you sure the actor wasn't playing the part of a pumpkin?

I would say ´persons´and ´people´ are used somewhat differenty.`

´People´ sounds too colloquial sometimes. I use ´people´when I´m talking about things in general, and ´persons´ when I´m being specific.

´English people...´ not ´English persons´
´A people has the right to decide...´ X ´People have the right to decide... ´

´A person has the right to decide...´

But I would say ´All those people have the right to decide...´; but I think ´persons´ fit as well as.

I think it´s a question of ´English usage´, not grammar.

Is it not common amongst the brits to pronounce the ´t´ in ´often´? I hear it some of-TEN... :-)

My British English teacher told me both are commun in England. "Of-ten" and "of-en".

Mike, perhaps you misheard the word “bumpkin” so you thought it is “pumpkin”.
When we say “bumpkin” we mean a country person regarded as unsophisticated.

Chlodwig die Krone, komm jy uit Neederland of Suid-Afrika?

Sorry for the pumpkin-bumpkin mistake but on BBC, for instance, you often get to hear 'often' with distinct 'T' in the middle. I don't think the BBC people want to sound like pumpkins - sorry bumpkins, ,do they?