Translation:This is the man whose wife is a teacher.
So this is the genetiv portion of these 4 lessons. But what is the difference between deren and dessen? Plural and singular?
Sm = subject of main clause
Ss = subject of subclause
The use of dessen / deren depends only on Sm.
If Sm = male singular then dessen regardless of gender of Ss and regardless of number of Ss.:
Das ist der Mann, dessen Sohn / Tochter / Haus / Regeln ich kenne.
If Sm = female singular then deren regardless of gender of Ss and regardless of number of Ss.:
Das ist die Frau, deren Onkel / Tante / Auto / Bilder ich toll finde.
If Sm = plural, then deren:
Das sind die Brüder / Schwestern / Kinder, deren Vater / Mutter / Haus / Geschwister wir malen.
And neuter patterns like masculine:
Das ist das Auto, dessen Kofferraum (m.) / Tür (f.) / Dach (n.) / Räder (pl.) kaputt ist/sind.
Sometimes "Das ist der Mann" or "Das ist die Frau" is followed by den, dem, die or der, but as in this sentence it can be dessen or deren. I'm really confused on which to use when. Any guidelines?
The form of the relative pronoun (RP) in German depends on gender, number and case.
Above, in the examples using dessen or deren, the RP is in genitive case.
Here's a good overview on German RPs: http://www.nthuleen.com/teach/grammar/relpronexpl.html
We accept "husband, wife" for Mann, Frau only in a possessive context such as mein Mann, dessen Frau etc.
This sentence has der Mann.
If you want to say "the husband" without saying whose husband it is, then use der Ehemann.
"That is the man whose woman is a teacher." was not accepted, but what is wrong? Duo says that the correct answer is: "This is the man whose wife is a teacher." Frau = woman seems a correct translation. And "Das = That" not correct?
"Frau" is better translated as "wife" in a possessive context; we don't typically use a possessive with "woman" in English. The possessive in German implies that the speaker and the woman are married, hence "wife."
"That" is fine for "das"; Duo's "correct answer" doesn't always stay entirely true to your particular answer; it often just gives you a random correct answer that may have something else worded differently from your answer, even if what you wrote wasn't wrong.
"This is the man whose wife is teacher." is indeed wrong, but where did you see that? It's not one of the accepted alternatives for this sentence.
When we speak about someone's role or profession, we often do not use the indefinite article ein.
This is getting ridiculous now.
In tips and notes Dessen is genitive for "the"
where are you getting the word whose?
maybe Duolingo German should be broken in 4 separate courses. 1. nom 2. acc 3. dat 4. gen
I have wasted so much effort on your grammar when all I really want is to get by in conversation
Hey, Duolingo: my page says that the right answer, in English, is "That is the man whose woman is a teacher." It isn't everyday English to say that a man has a woman, which implies ownership and is offensive. We would say that he has a "wife." The German "Frau" in the case of this sentence means wife and not woman. We might in English say that someone "had" a woman, as in, had sex with her, but this doesn't seem to be what the German sentence is implying.
I'm not sure where you're seeing "woman," but you'll see at the top of this page that Duo is translating "Frau" as "wife," which is, as you said, what is implied in the German.
Yes--strangely, the top of this page says something different than the page with the actual exercise. That still says "That is the man whose woman is a teacher."