I would suggest in this sentence the emphasis is on killing a bear without tools such as a knife. It does not mean he had nothing on his hands he could be wearing gloves. In this type of sentence though 'his' would usually be used. Although when it is not so dramatic you could say something like she washed up with bare hands meaning she didn't wear gloves. I do not think there can be any question as to whose bare hands are being used. I am an English English native speaker
"the bear" would mean that a reference to the hapless bear has already been established, and that would require reordering of the czech sentence, preferably along with adding the demo pronoun as well: "zabil (toho) medvěda holýma rukama." try searching for the contextual differences associated with the (in)definitiveness of the bear in "he killed a/the bear with a knife" on google books.
Just when I thought that instrumental declensions seem easier than the other declensions, Duo presented me with “rukama” which didn't seem to fit. So I looked it up ( https://cs.wiktionary.org/wiki/ruka ) and discovered that “ruka” declined in singular and plural as well at dual!!!!! What kind of words decline in dual? Only body parts? Socks? Windshield wipers? Do the adjectives for "dual" nouns decline in the same way?
Does this limit to only body parts, or other objects in the physical world too, presuming that they only appear in pairs? There perhaps aren't any such objects in the world, so that the question might end up futile, asinine even. But I heard about something similar in Belarusian, and was surprised to hear that it was preserved in Czech as well. There are also no Tips & Notes for this lecture; have they been removed within the past two years? (In the browser version of Duolingo)
It's pretty much only: ruka, noha, oko, ucho, that have these special plural forms which used to be dual. Even the nominative plural is unexpected for three of them: ruce, oči, uši, (and nohy looks like a regular plural). Also ramena (shoulders) and kolena (knees) have unusual forms but only in some plural cases.
"oko" can mean a number of things that are similar in shape to the human eye, for instance a hole in a fabric or woven net/mesh, the eye of a storm, a tarn (mountain lake) etc. Similarly, "ucho" can be a handle of a pot or mug, or even the eye of a needle (ucho jehly). When they don't refer to human organs, they have regular plural forms. For example:
- Dívala se na mě svýma modrýma očima. - She looked at me with her blue eyes.
- Měl ponožku se dvěma velkými kulatými oky. - He had a sock with two large round holes.
- Kluk s červenýma ušima - A boy with red ears
- Hrnec s kovovými uchy - A pot with metal handles
@Agnus Oinas Thanks for mentioning the thing with the mutliple meanings of certain words like oko; I would have otherwise stumbled across them in confusion when hearing the word eye and therefore think about eyes in sockets (rather than eye-sockets) As for the ending they take for the instrumental case, this is less of an inconvenience as I have come across such issues in Polish beforehand, and in Czech, while I wished that some grammatical endings were clearer to be distinguished, they are easier to remember.
Thanks a lot, this is truly helpful! :-)