Two types of boundaries, between morphemes and within their exponents, corresponding to two kinds of segmentation, in combination, reveal typologically different units of the plane of expression (Gordina’s Rule) and, hence, types of languages, viz. (1) Phonemic Languages. Vowel and consonant phonemes revealed as a result of the non-coincidence of morpheme- and syllable boundaries, yielded due to the presence of zero-inflexion forms in the paradigm and resyllabation respectively, cf. /to-ka/ - morphologically, tok-Ø - tok-а .’current (nom. and gen.)’. (2) Isolating Languages (erroneously, syllabic ). The boundaries of the morpheme exponent coinciding with those of the minimal unit of the plane of expression, alias paradigmatic inventory unit, not opposed as ‘consonant’ and ‘vowel’ phonemes to form /C/ + /V/ combinations, or phonemic syllables (‘constructional units’). (3) Intermediate Type (erroneously, phonemic languages ). Partly admitted type (1) resyllabation yielding phonemes (e.g. Engl. /i:/ and /d/ in read - read-ing - rea-ding ) vs. froms with no resyllabation ( living ) and no morpheme boundaries ( pity ), plus suppletion forms of the sit-sat type (erroneously, ‘inner inflexion forms’). The use, jointly, of the two kinds of boundaries relies on the principle of the dual segmentation, which implies, in turn, the connection of the units of the plane of expression with meaning.