If you will stay here, then you won't have any success.
If we always buy the newest computers, then we will be quickly poor.
If John will come to the party, then I will not come.
Do I have to add the then in all sentences?
I also know sentences that don't contain the then.
A song is called:
If I like it I do it.
Is there maybe a rule when to use then and when not?
P.S. I'm not even sure if the commas are right.
***NOT A TEACHER***(1) Most books say that we don't have to use "then." It's just a word in our mind, but you don't have to say it. Native speakers "think" it. (2) Remember the "rule": usually you use the present tense in the "if" part: (a)If you STAY here, (then) you will be unsuccessful. (b)If we always BUY the latest computers, (then) we will soon be poor. (c)If John COMES to the party, (then) I won't. (3) Your commas are fine. Thank you.