Translation:the letter I
It's a general problem with hints for words that start with an apostrophe.
Duolingo's programmers know about this and are working on a fix (but I don't know when it will be ready).
Please don't report "hints are wrong or missing" for words starting with an apostrophe -- it's a known issue and reporting it won't get it fixed any faster.
For now, you will have to learn these words either by guessing and then looking at the correction afterwards, or by looking them up in a Klingon dictionary.
Alternatively, if you want to rely solely on the hints, you would have to pause using Duolingo for Klingon until this bug has been fixed.