[EnglishTeacher79]

People call it the "if-then" clause, but then most of the time we just see "If....., ...." - i.e. without the "then" starting the other clause. So it's:

1) "If he hits me, I will kill him."

rather than:

2) "If he hits me, then I will kill him."

Is it ungrammatical to use "then" as in (2)? I don't seem to see this kind of sentence often and I think I read somewhere that it's either unnecessary to use "then" or that it's outrightly ungrammatical to use "then".

So is it wrong to use "then"? If so, why do people call it this "if-then".

In the IELTS Handbook 2007, I came across this sentence:

"If texts contain technical terms then a simple glossary is provided"

And the above sentence doesn't have a comma (,) before "then".

So this brings me to a futher question on the comma - would a sentence be possible without a comma?

Grateful for some comments