Sheila Wilson Feb 15, 2009:

A comment for the record - it's certainly used in Br Eng too, to mean all the things Gary D mentioned (I'm a Londoner, by the way). Is it correct? As a British English teacher, I'd say that it's normal acceptable spoken English, incorrect written English

Rafal Korycinski (asker) Feb 15, 2009:

It's clear for me, that 'then' goes well with 'if' in the first part of the sentence. I was just wondering if using 'then' alone (without 'if') is perceived as a mistake by the native English users, or not.

Just a short clarification: the sentence I've quoted is the only sentence in English, and also it is the whole message. There are no related sentences before nor after the quoted sentence, so saying 'depends on what comes before' makes not much sense, because the answer is clear: nothing.

Judging by the geographical location of 'agree-ers' I would guess, that this way of speaking is not used in British English, but is used in the US/Canadian English, where 'then' is sometimes used instead of 'just'. However, this is a casual, not a formal language.

As both suggestions were only the partial answer to my question, I'm assiginnig points to Jack, who was first to answer.

Thanks to everyone, who participated in making things more clear for me :-)

Gary D Feb 14, 2009:

another example; If you want to get to my place, then take exit No 5.
you could also use; if you want to get to my place, take exit No 5
but it sounds better with "then" as it is a bit like saying "please take exit No 5"
It is a more polite with 'then'