All 3 Uses

distinguish
in
Severance
(Edited)

Yes, I speak Mandarin with my parents, I answered, thankful that the language does not require tenses distinguishing past, present, and future.
p. 87.7 *

distinguishing = treating as different
Day and night seemed indistinguishable, the dividing line between them membranic.
p. 195.1

indistinguishable = not recognizable as different

standard prefix: The prefix "in-" in indistinguishable means not and reverses the meaning of distinguishable. This is the same pattern you see in words like invisible, incomplete, and insecure.
Past and present become indistinguishable.
p. 222.1

Definitions:

(1) (distinguish as in: distinguish fact from opinion)
recognize or treat as different
(2) (distinguish as in: her accent distinguishes her)
to set apart or to be an identifying characteristic
(3) (distinguish as in: the distinguished scientist)
seen or demonstrated as different -- especially as worthy of admiration
(4) (distinguish as in: distinguish a vague shape)
perceive something that is barely perceptible
(5) (meaning too rare to warrant focus)