1st Conditionals with modal verbs

[Belles1654]

I am a little confused about first conditionals and what all applies.
If I say:
1) If you go to Rome, you'll see the Colosseum. It is 1st conditional

Is it the same as saying

2) You must see the Colosseum, if you go to Rome.

or

3) If you go to Rome, you have to see the Colosseum.

What role does modal verbs play in conditionals. Are my last two sentences still 1st conditionals? Help! Thanks in advance, Annabelle

[Sarah113]

Hi Annabelle
I know that the frst conditional is used to talk about things that are possible in the futre.(it's possible that it will be sunny . So (liklely result) we'll go to the beach tomorrow)
I think that the result in your second sentence is an obligation related to the condition expressed.
And the result expressed in the second sentence is a necessity ( So the second and the third sentences are not conditional)

[Inga]

Must in your sentence, as I guess, means emphatic advice. But I can't understand the use of have to. As far as I know, it usually means 'obligation, necessity, arising out of circumstances'. (When something forces you to do something.)
_________________
I am an incurable optimist.

[Belles1654]

Okay, so conditional really means one thing depends on the other. Thank you Sarah113:) -Belles