This article is devoted to the research of psychophysiological markers of language competence and individual sensitive periods of English learning of the pupils of specialized linguistic school. Third form pupils participated in our research. We used 14 indicators to determine the language competence including grammar, lexis, and orthography. Functional inter-hemispheric asymmetry was measured by using the technology of computer laterometry which provides quantification of direction and efficiency of inter-hemispheric asymmetry by sound localization function (SLF). We established that the number of linguistic parameters is excessive. So we can conduct only 4 parameters with no less informative content. We found strong correlation between 4 parameters of laterometry and 7 parameters of language competence. We came to the conclusion that the level of English acquisition of the pupils with the oppression oh the right hemisphere is authentically upper than that of the pupils with the oppression of the left hemisphere.