Declension of nasal stem nouns differs from that of standard consonant and vowel stems. The four nasal stem types discussed in the paper are not strict categories, a wide range of nouns show variance in the use of suffixes characteristic of one or another stem type, and also several examples of semantic split can be observed. Data obtained from the internet using a search engine show the distribution of the alternating forms, the tendencies of certain changes of stem types and also prove the spreading of unstable n-stems and velar nasal stems. The most complex phenomenon among Khalkha nasal stem types is the unstable n which is not simply a lexically encoded empty morpheme or a phonological feature in the declension paradigm of a particular noun class, but it has certain grammatical functions as well.