First and second conditionals

The first conditional is for a real possibility: if plus the present, then will: if it rains, we will stay home. Never put will after if.

The second conditional is for an imagined situation: if plus the past simple, then would: if I had more time, I would travel. With be, careful English uses were for every person: if I were you.

When the if clause comes first, put a comma after it; when it comes second, no comma: we will stay home if it rains.