A recent report on the BBC News website had this to say:
“The district committees approve plans weekly without informing me,” Interior Minister Eli Yishai, the chairman of the ultra-Orthodox Shas party, told Israel Radio on Wednesday morning.
“If I’d have known, I would have postponed the authorisation by a week or two since we had no intention of provoking anyone.” (March 10th, 2010)
If I’d have known - not If I’d known … Whose wording was this, I wonder? Eli Yishai’s? Israel Radio’s? Or the BBC’s? Interesting, anyway, that the BBC didn’t feel the need to correct it. Maybe they didn’t even notice it, so frequent it has become.
Out of interest, I ran a check using – just for fun – this data base of cinema screenplays (thanks to Nik Peachey for this link) to see how often – and how far back – the “if I’d have known…” conditional occurs. Here are some examples:
Sorry about that. If I’d have known, I’d take you to New Orleans (Apocalypse Now 1979)
If I’d have known this was going to be the last time me and Bubba… (Forrest Gump 1994)
Yeah? I’d have brought my gloves if I’d have known (Lock Stock and Two Smoking Barrels 1998)
If I’d've known this was gonna happen, I’d have brought my motherfuckin’ gun! Help! (The Rock, 1996)
These examples suggest that the phraseology is most common with the verb know – forming what amounts to a fixed expression. But what about these?
I couldn’t live with myself if I’d have hit her. (Cinderella Man 2005)
If I’d have fallen asleep then I would have ended up in a ditch with a headache .(Signs 2002)
If I’d have went to jail, I’d be getting out today (Jarhead 2005)
If I’d have been careful piloting that reconnaissance plane you wouldn’t have had the chance to take the pictures
(Rear Window 1954)
All of which raises the question – if this usage is so well-established - should we accept it when our students produce it?