"typewriter" is one of those many words which can be spelled solely with the top line of letters on a QWERTY keyboard

'Typewriter' can indeed be spelled using only letters from the top row of a QWERTY keyboard: t-y-p-e-w-r-i-t-e-r. All these letters (q, w, e, r, t, y, u, i, o, p) are on the top row. Other examples include 'proprietor', 'repertoire', 'perpetuity', and 'peppertree'. This is a well-known keyboard curiosity. The claim is true and easily verified by looking at the letter positions on a QWERTY keyboard.