First Conditional Alternate Forms
Going to'Going to' is often used to replace 'will' in the first conditional. This is often done to emphasize a certain result.
Example
If you apply to that school with your excellent marks, you're going to be accepted!
'Going to' is also used to mean 'intend to' after 'if'.
Example
If you're going to skip school, you certainly won't pass your exams.
Present Perfect
With the first conditional, the present perfect is used to focus on the completion of an action.
Example
We'll meet for lunch if you've finished your work.
Should
'Should' implies that something is possible, but improbable.
Example
If he should arrive, we'll invite him along to dinner.
This is stronger than in the second conditional in which an unreal or imaginary situation is presented. Compare:
If he studied, he'd pass the exam.
In this example, I am sure that the student will NOT pass the exam, the second conditional expresses an IMAGINARY situation.
If he should study, he'll pass the exam.
In this case, I think that the student will probably not study, but if he does, he'll pass the exam.
Happen to / Should happen to
These two forms emphasize the chance nature of the conditional. In this way, the condition, while still true, is a less likely to occur.
Examples
If they happen to come to town, we'll have dinner.
If he should happen to get stuck in that town, he'll be able to find a hotel room for the night.
Modals in Result Clause
Modals can be used in the result clause to indicate future possibilties, permission and advice.
Examples
If you finish your homework, you can go out and play.
You should see a doctor if you continue to feel bad.
If you arrive early, you might give Tom a call.
If and Adjectives
With the verb 'to be' plus and adjective, the subject and verb of the 'if' clause can be omitted. The result clause follows in the imperative form.
Example
If interested, apply for the position.
Provided (that), As long as
'Provided (that)' and 'as long as' are used to instead of 'if' to show specific conditions that must be met in order for something to happen.
Example
Provided he finishes his studies, he'll find an excellent job.
As long as she pays off the loan, the house will be hers at the end of next year.
