What Will Happen?
Zero Conditional
Use the zero conditional if an action always occurs as the result of another action. The zero conditional is used to express conditions that are always true.
Example:
It's good to be prepared to buy a new vehicle if the problems with the current one persists.
The loan is on consignment if the credit score is reported above 650.
The present simple is used in both the 'if' clause and the result clause.
'If' clause - present simple + , + result clause - present simple
It's good to be prepared to buy a new vehicle if the problems with the current one persists.
The loan is on consignment if the credit score is reported above 650.
Do not use a comma, when placing the result clause first.
The loan is on consignment if the credit score is reported above 650.
First Conditional
Use the first, or 'real', conditional if an action will occur if something happens. The first conditional is used when a result is realistically possible.
'If' clause - present simple + , + result clause - future with will
The minimum balance fee will be waived if the charges clear on time.
What will be your staff's turnaround time on this project if we do it in two weeks?
Do not use a comma, when placing the result clause first.
The landlord will accept a letter of credit if that's the best we can do on short notice.
'Unless' is also used in the first conditional to mean 'if not'.
If he doesn't come soon, we won't go to lunch = Unless he comes, we won't go to lunch.
Use of 'May' and 'Might' in the First Conditional
When a future result is not certain based on a condition, use 'may' or 'might'.
'If' clause - present simple + , + result clause - 'may / might' + verb
We might see a good return on investment if the market continues to improve.
We will not disturb you if you give the details of itemized statements.