In formal English you can leave out if and move the helper verb to the front: Should you need help, Were I in your shoes, Had I known. The meaning doesn't change, but the tone becomes polished, which is why you see these forms in business emails, contracts, speeches and news writing.
The pattern
Should you need anything, please call me.
Had I known, I would have come earlier.
Were the city to close the bridge, traffic would be terrible.
01Should: a polite first conditional
Should + subject + base verb replaces if + present. It makes a possibility sound a little less likely and a lot more polite, so it's everywhere in customer service emails. The negative is Should you not.
- Should you have any questions, please contact our office.
- Should the package arrive damaged, call us within two days.
- Should you not receive a confirmation, check your spam folder.
02Were: the second conditional
Use Were + subject before an adjective, noun or place, and Were + subject + to + verb before an action. Always use were, even with I, he, she and it. For the negative, say Were it not for + noun.
- Were I in your position, I'd ask for a raise.
- Were the company to expand, it would need more space.
- Were it not for my sister, I would never visit Ohio.
03Had: the third conditional
Had + subject + past participle replaces if + past perfect. This is the one you'll hear most in everyday American speech, especially Had I known. The negative is Had I not, never Hadn't I.
- Had we left earlier, we would have caught the train.
- Had she not taken the job in Austin, she'd still be in Ohio.
- Had it not been for the GPS, we would have gotten lost.
04Other ways to say if
But for + noun means "if it weren't for" or "if it hadn't been for." Otherwise means "if not." Supposing asks someone to imagine something. An imperative + and shows a good result, and an imperative + or shows a warning.
| With if | Without if |
|---|---|
| If you need help, ask me. | Should you need help, ask me. |
| If I were you, I'd wait. | Were I you, I'd wait. |
| If I had known, I'd have come. | Had I known, I'd have come. |
| If it hadn't been for you, I'd have failed. | But for you, I'd have failed. |
| If you don't leave now, you'll be late. | Leave now, or you'll be late. |
| If you practice daily, you'll improve. | Practice daily, and you'll improve. |
05Common mistakes
Should you will need help, call me.
Should you need help, call me.
Should is already the helper verb, so the next verb is the base form.
Hadn't I checked, I'd have missed it.
Had I not checked, I'd have missed it.
Inverted conditionals don't use contractions with not. Put not after the subject.
Was I in charge, I'd change the schedule.
Were I in charge, I'd change the schedule.
Only were works in an inverted second conditional, even with I.
Had I knew about the sale, I'd have waited.
Had I known about the sale, I'd have waited.
Had needs the past participle: known, not knew.