if + [subject] + [past simple], [subject] + would + [verb]
[subject] + would + [verb] + if + [subject] + [past simple]
The second conditional imagines something different from the real world: a situation that isn't true now, or one you don't really expect. The if part uses the past simple, but the meaning is about now or the future. The other part uses would and the base verb.
In speech and messages, would becomes 'd: I'd, she'd, we'd. The negative is wouldn't.
When the if part comes first, put a comma after it. When it comes second, you don't need one.
The first conditional (if + present, will) is for something that can really happen. The second is for something unreal or unlikely.
After if, you can use were for every person, also with I, he, she and it. If I were you gives advice. If I was is common in speech, but were is better in writing.
Use could for "would be able to" and might for "would perhaps".
In this pattern, would goes in the other part, not after if.