G4417–πταίω–ptaiō

I ask, however, "Have they stumbled so as to be finally ruined?" No, indeed; but by their lapse salvation has come to the Gentiles in order to arouse the jealousy of the descendants of Israel;

ἔπταισαν eptaisan “they did stumble”

A man who has kept the Law as a whole, but has failed to keep some one command, has become guilty of violating all.

πταίσῃ ptaisē “may stumble”

For we often stumble and fall, all of us. If there is any one who never stumbles in speech, that man has reached maturity of character and is able to curb his whole nature.

πταίομεν ptaiomen “we stumble”πταίει, ptaiei “does stumble,”

For this reason, brethren, be all the more in earnest to make sure that God has called you and chosen you; for it is certain that so long as you practise these things, you will never stumble.

πταίσητέ ptaisēte “shall you stumble”