The difference in pronunciation of words that are spelled with or without apostrophe is sometimes difficult to notice, for example, морквяний (without apostrophe) and черв'як (with apostrophe), thus even the native speakers may have problems with spelling. There is a set of rules according to which you can distinguish the words that should be spelled with or without apostrophe. In general, the apostrophe is used, with some exceptions,before an iotated vowel (ю, я,є,ї) and after the labial consonants б (e.g. б'ю), в (e.g. зв'язок), м (e.g. м'ясо), п (e.g. п'ю ) and ф (e.g. торф'яний), and also, in some cases, after р occurring at the end of a syllable (e.g. матір'ю ).