Letters that make perseveration
s, a, o, e, n, p, r, t, i, v are letters that make 'perseveration'
Words within perseveration
ER, pe, ti, Erse, ERA, ration, at, ratio, SE, sever, Eve, eve, on, ever, rat, RA, eV, Io, ion, Ra, At, Er, Se, Ti, era are words within 'perseveration'