The First conditional is often used:
If you start with the if clause then you need to separate it from the main clause with a comma.
If clause (Condition) | Comma | Main Clause (Result) |
If + present Simple | , | Subject + will/other modal + base verb |
If you start the sentence with the main clause you must not separate it from the If clause with a comma.
Main Clause (Result) | If Clause (Condition) |
Subject + will/other modal + base verb | if + present Simple |
Examples:
If I see her | , | I will tell her I love her. |
If it rains | , | I will take an umbrella |
She‘ll be late | if the train is delayed |
She’ll miss the bus | if she doesn’t leave soon |
You can also use modals in the main clause
Examples:
If I go to Paris, I might visit the Eifel tower.
If you want to, you may eat some of my fries.
If you want information, you should go to the front desk.