Inverted conditionals

• "Had I known" = "If I had known". Drop "if" and put "had" first.
• "Should you need" = "If you need". A polite, formal first conditional.
• "Were the government to raise" = "If the government raised". Formal second conditional.
• In negative inversion, "not" goes after the subject and is never contracted: "Had she not".
• "Should + subject + base verb" replaces "If the train arrives late".
• They sound formal. In everyday speech, "if" is more natural.

• Had I known about the traffic, I would have left earlier.
• Should you need any help, please call me.
• Were the government to raise taxes, there would be protests.
• Had she not helped us, we would have failed.
• Should the train arrive late, start without us.
• Formal writing, contracts and official notices

Pick an answer to see the rule behind it.

More in Formal Structures

• The subjunctive
• The unreal past