"yInroH nejbeH Hoqra'."

Translation: The tricorder is ready to search for life signs.

[JamesTWils]

yInroH is a singular, right?

[jdmcowan]

It's sort of hard to say for sure. I don't believe we've seen it used in canon ever and the definition in The Klingon Dictionary has it in the plural, but is that referring to a set of life signs, or life signs as an uncountable mass? I think I would be fine accepting it as a single set of life signs until we get further clarification. But fortunately, since plural markers are optional in Klingon, a sentence like this one from the course could be referring to them as either a single set, multiple sets, or an indistinguishable mass of life signs.

[ZakArranda]

If memory serves, ST characters always used "life signs" as plural, even the life signs of an individual. Presumably the term refers to the set of measurements like pulse, blood pressure, etc.

[jdmcowan]

Sure, in English. Based on how it's lexicalized in The Klingon Dictionary, until I have other evidence, I'm going to assume that it is a mass noun in Klingon and thus it wouldn't normally take a plural marker.