Job 9:20 New English Translation

²⁰Although I am innocent,^[a]
my mouth^[b] would condemn me,^[c]
although I am blameless,
it would declare me perverse.^[d]

Job 9:20 tn The idea is the same as that expressed in v. 15, although here the imperfect verb is used and not the perfect. Once again with the concessive clause (“although I am right”) Job knows that in a legal dispute he would be confused and would end up arguing against himself.
Job 9:20 tn Some commentators wish to change this to “his mouth,” meaning God’s response to Job’s complaints. But the MT is far more expressive, and “my mouth” fits the context in which Job is saying that even though he is innocent, if he spoke in a court setting in the presence of God he would be overwhelmed, confused, and no doubt condemn himself.
Job 9:20 tn The verb has the declarative sense in the Hiphil, “to declare guilty [or wicked]” or “to condemn.”
Job 9:20 tn The verb עָקַשׁ (ʿaqash) means “to be twisted; to be tortuous.” The Piel has a meaning “to bend; to twist” (Mic 3:9) and “to pervert” (Isa 59:8). The form here is classified as a Hiphil, with the softening of the vowel i (see GKC 147 §53.n). It would then also be a declarative use of the Hiphil.

New English Translation (NET)