 The mark also helps to distinguish different grammatical forms with otherwise the same written form, but are pronounced differently.Between 1927 and 1989, the ogonek denoted lowering in vowels, and, since 1976, in consonants as well, in the International Phonetic Alphabet (IPA).While the obsolete diacritic has also been identified as the left half ring diacritic , many publications of the IPA used the ogonek.