if ,then in sentence

[english_learn]

I have seen some [FONT=&quot]sentence have "if and then ", and some are only have "if"[/FONT]

For example

If they have been updated, then please change the status to closed or open.
If they have been updated, please change the status to closed or open.


which one is correct above?


Also please tell me where should "Then" be used and not.

 

[5jj]

Both are fine. 'Then' is perhaps a reminder that the utterance has started with 'if' - it is saying, "in that case...'. The longer the if-clause, the more likely we are to use 'then', In my opinion.