Choose which word(s) are in non-standard English.She doesn't know 'im.

Correctly written English could be called Standard English. 'Standard English' might be described as the English language as it is spoken and written by educated native users.  In standard English, you should 'keep your pronouns consistent'. For example, it would be wrong to say 'the children collected HIS prizes'. What you ought to say is 'the children collected THEIR prizes'. Basically, Standard English is about choosing the right word to make a sentence understandable.