I'm afraid but I have to say some native speakers confuse the contraction [it's] with the possessive pronoun [its]. A graduate from Cambridge University once insisted that you need an apostrophe after [t], and the apostrophe + s means possessive. Another thirty-year-old man from Britain said that you should put an apostrophe between [t] and [s].
Yesterday an ALT, which means assitant language teacher, said to me,"it's awkward to put an apostrophe after [s], and no [s] after the apostrophe when I asked if it's OK to write [girls school] and if you should write [girls' school].
Any languages are changing always. So this might be one of the case. Do you think there are not a few native speakers who think possessive forms should have an apostrophe + [s]?
Or do you already use the word [it's] as the possessive pronoun?
I hope you will help me.
Thank you very much in advance.