The grammatical specificity of scientific text is grounded not only on high frequency, but also on rarely used grammatical forms and construction. On the one hand the communicative standards and the discourse norms of the depersonalized academic interaction can be carried out with grammatical dominants: the passive, 3th person, generalized present forms etc. On the other hand the means of grammatical periphery (explicit I-references, interrogatives, imperatives, past tense forms etc.) belong to pragmatic devices to further forwards and to control the scientific argument.