、。
She studies not only language but literature as well.
Literal
She [topic-は] language [topic-は] of-course, literature [also-も] is-researching.
XはもちろんY(も) is a fixed pattern that scopes a statement past an obvious case to include something further: 'X, of course — and Y as well.' The はもちろん half presents X as the unsurprising baseline, then も on Y bolts on the additional case. Useful in writing and formal speech for 'not only X but also Y' phrasing without the more bookish ばかりか or のみならず. 研究する is the formal verb for academic research, distinct from 勉強する ('study') — it implies original investigation rather than learning what's already known. 言語 (general 'language') and 文学 ('literature') name two adjacent but distinct fields one might pursue at university.