A new report on the potential of solar energy, by leading business consultants Ernst & Young, tells us (p.11) that ‘increased efficiency of manufacturing and improvements in non poly silicon costs has lead to cost reductions overall’ Aaargh: the old lead vs. led problem: they sound the same (in some meanings, at least) but the past tense and participle of the verb ‘to lead’ is led. But worse than this is the Executive Summary which the report opens with, where we read that:
Due to it’s relative simplicity as a passive asset, solar has been observed as an entry point for large corporates.
This should of course say ‘due to its relative simplicity …’. Maybe I’m just being pedantic, but for me the authority of the report was somewhat diminished by these basic errors. Sure, there are plenty of texts where mistakes like this don’t really matter, but it’s reasonable to expect that a serious report, from an organisation whose motto is ‘Quality In Everything We Do’, should get these things right.
Having said that, it isn’t surprising that this is one of the commonest of all punctuation errors in English. The problem lies in the fact that we use apostrophes for two different functions: either to show either possession (a genitive), or to indicate the omission of one or more letters – but this simple ‘rule’ doesn’t apply in the case of the pronoun it. (Apostrophes are sometimes also used to form plurals, as in ‘the word committee contains two m’s, two t’s, and two e’s’, or ‘in the 1960’s’, but these uses are – or should be – very rare.) So we can say My sister’s baby (possession: the baby that belongs to my sister), or My sister’s a baby (omission: my sister IS a baby), or My sister’s had a baby (omission again: my sister HAS had a baby).
When attached to a noun (or to someone’s name) ‘S can have all these uses. But confusingly, this doesn’t happen when we’re using the word it. In this case, the ‘S can only be used to indicate omission (for IT IS or IT HAS: It’s been a hard day’s night), but not to show possession. To show possession, we use its without an apostrophe: It’s lost its handle. Why? There is no logic in this – but it’s a mistake to expect language to be logical. Indeed the OED reports that its was (as we would expect) formed from IT and the possessive or genitive ‘S
and [was] at first commonly written it’s, a spelling retained by some to the beginning of the 19th c.
So the form its is relatively modern and (says the OED) ‘does not appear in any of the works of Shakespeare published in his lifetime’.
I hope that clears things up, but perhaps all this is another argument for a proposal made in one of our earlier postings: that apostrophes should be abolished altogether, on the grounds that they cause more harm than good.

It’s a mistake that has appeared all sorts of reputable places. In the last nine months, and without going out of my way to look for it, I’ve seen it on the websites of The Economist, The NYT, The Boston Globe, The Plain English Campaign, and Language Log. I also saw it in a book I read recently, from a reputable publisher.
Robert Burchfield said it might be better to do away with the apostrophe in the cases of plurals and possession. I’d like to think people could just learn how to use it, but I expect the problem to get worse rather than better. It has always been a troublesome mark, as this short history (PDF) shows.
I taught “its” was a separate word like “his” for “he” and “her” for “she.” I am a bit confused to learn that its initial form was actually “it’s”.
[…] most misused word in the English language; Michael Rundell at Macmillan Dictionary Blog pondered it’s and its; and K International examined irregular verbs. Motivated Grammar hashed out all of a sudden […]