NET
19 You will no longer see a defiant people whose language you do not comprehend, whose derisive speech you do not understand.
Darby
19 Thou shalt no more see the fierce people, a people of a deeper speech than thou canst comprehend, of a stammering tongue that cannot be understood.
KJV
19 Thou shalt not see a fierce people, a people of a deeper speech than thou canst perceive; of a stammering tongue, [that thou canst] not understand.