speak pseak sepak espak pesak epsak spaek psaek sapek aspek pasek apsek seapk esapk saepk asepk easpk aespk peask epask paesk apesk eapsk aepsk speka pseka sepka espka peska epska spkea pskea skpea kspea pksea kpsea sekpa eskpa skepa ksepa ekspa kespa peksa epksa pkesa kpesa ekpsa kepsa spake psake sapke aspke paske apske spkae pskae skpae kspae pksae kpsae sakpe askpe skape ksape akspe kaspe pakse apkse pkase kpase akpse kapse seakp esakp saekp asekp easkp aeskp sekap eskap skeap kseap eksap kesap sakep askep skaep ksaep aksep kasep eaksp aeksp ekasp keasp akesp kaesp peaks epaks paeks apeks eapks aepks pekas epkas pkeas kpeas ekpas kepas pakes apkes pkaes kpaes akpes kapes eakps aekps ekaps keaps akeps kaeps
Note: these 'words' (valid or invalid) are all the permutations of the word speak. These words are obtained by scrambling the letters in speak.