In order to subsidize the practice of linguistic analysis of Portuguese language teachers, from the sociointeractionism viewpoint, this study aims at analyzing how the linguistic resources are systematized in the construction of an emergent textual genre, the blog. The data are texts collected from on-line diaries available on the Internet in March 2004. As the blog language pertains to a typically virtual environment as well as to a predominantly youth group, it is placed between speech and writing, and presents characteristics that reflect how the grammatical, lexical and semantic choices of the Internet browser are motivated by the situational contexts in which such a language is produced. The understanding of this process can help the teacher face virtual writing interferences when dealing with student writings.