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According to the gigantic word list from Orchy and a Perl script I wrote, the following are the 48 letter pairs that never show up in English words:
bq, cj, cv, cx, fq, fv, fx, gq, gx, hx, jb, jf, jg, jh, jq, jt, jw, jx, jy, jz, kq, kz, px, qc, qf, qg, qh, qj, qk, qm, qn, qp, qq, qv, qx, qy, qz, vb, vj, vq, vw, vx, wq, xj, xk, xz, zf, zx
Note, however, that several of these are common abbreviations (CV for “Curriculum Vitae”, FX for “effects”, GQ for “Gentleman’s Quarterly”, VB for “Visual Basic”, VW for “Volkswagen”, etc.) and others show up in proper nouns and radio station callsigns.

















