English Theasurus that shows all the ways the English word is translated from the original Greek and Hebrew.
English Theasurus from the Hebrew and Greek Strong's Dictionary
affirm 1226 ** diabebaioomai ** {affirm} constantly.
affirm 1340 ** diischurizomai ** confidently (constantly) {affirm}.
affirm 5335 ** phasko ** {affirm}, profess, say.
affirm 5346 ** phemi ** {affirm}, say.