The subject of this article is Antoni Malecki's conception of description of some vocalic and consonantal questions given in his 'Larger Grammar of Polish Language' (Lvov, 1863). The definitions, repartitions and descriptions of vowels' and consonants' articulation are analyzed, as well as the relation between a phone and a letter. The vowels' twofold forms are also described in this study. It was ascertained that the clasifications and descriptions given in the grammar are highly incorrect. Malecki's statements often aren't precise and explicit and all his remarks prove the grammarian's irresolution. It seems that he oscillates between the contemporary and historical point of view - the consciousness of the various origin of particular sounds has left its impress on the way of description. The bases of classification, as in the others Polish grammars of the 19th century, aren't homogeneous - Malecki assumed three criteria: genetic, sound and articulatory, however, he often uses them inconsistently that led to their mixing. Also the descriptions of vowels' twofold forms may make serious reservations. Still it has to be remarked that Malecki hasn't made the same mistakes as the grammarians before him and for example he distinguishes a phone and its graphic sign. However, he understands the term 'letter' differently than we do it today - he defines digraphs as the letters too, which proves that for Malecki this term is rather similar to the nowaday's 'phonogram'. Nevertheless, it should be remarked that in the examined grammar the vowels and consonants were defined correctly and above all in a quite modern way, for the role of speech organs in making sounds was also considered.