"Worf and Torg hate each other."
Translation:muSchuq wo'rIv torgh je.
Thank you all. So the verb is 'muS' (hate). That was my mistake. And suffix '-chuq' means each other. According to 'the Klingon dictionary', '-chuq' is a type 1 suffix (meaning its position compared to other kinds, if any) As Worf and Torg are hating (they), and there is no other subject (other then the one already expressed with - chuq suffix), it takes no prefix. If I wanted to express that Worf and Torg hate me instead of each other, it would be 'mumuS wor'Iv torgh je'?
For the most part, Klingon doesn't have consonant clusters. That means that whenever two consonants appear next to eachother they must belong to separate syllables. The exceptions are syllable final -rgh, -w' and -y' and an additional note on that rule is that ch, gh, ng, and tlh are each considered a single consonant. But the point I'm really trying to make is that there is no verb S and no verb Schuq, so we can't interpret the first two letters of this sentence as being the prefix mu-. Since there are no consonant clusters, we must split the S and the ch in that first word to give us muS and chuq. Now reanalyze it and see if it makes more sense.
It's actually a good sign and a normal step in learning Klingon that you start to see/hear prefixes when they are really part of the verb. Eventually your eye/ear will pick out the verb quickly, and you'll only be confused by things like the noun lulIgh (refuge) the way chemistry majors are confused by reading the English verb unionize (un-ionize?)
Since we are writing Klingon with the Roman character set, we also use the Roman punctuation marks and you will find that sentences in Duolingo usually end with a full stop, a question mark, or an exclamation mark.
The qaghwI' is not a punctuation mark of any kind and is not used to mark the end of a sentence. It is a full letter of the alphabet and only appears when it is proper for the spelling of a word. Most Klingon roots are made up of consonant-vowel-consonant and it is much rarer to see a word that is only consonant-vowel. However the noun conjunction je is exactly such a word and ends with the vowel, not a qaghwI' or any other consonant.