A bstract String theory on AdS 3 × S $$ \mathbbm{T} T 4 with one unit ( k = 1) of NS-NS flux is considered in the hybrid formalism Berkovits, Vafa & Witten (BVW). Using free field realisation world-sheet at 1, we identify explicitly BRST cohomology classes corresponding to some low-lying states dual CFT. ...