Sind ihnen vs Ist ihnen
Came across an example in Dativ, lesson 4: "Ist ihnen schlecht?" (Are they bad?) As far as I know, shouldn't it be "Sind ihnen schlecht?"
(ihnen here is the dativ of plural 'they', sie)
@Drekir: your example "ist ihnen schlecht" means "are they feeling bad/ill" If you had written "ist Ihnen schlecht" it would have meant "Are you feeling bad/ill". The only difference is the capital in Ihnen (you). Anyway: keep in mind that it is an impersonal construction with the verb in singular. More examples: mir ist kalt, mir ist warm, mir ist übel (move away, he is going to throw up!!)
I think Drekir's question is about why the sein has been conjugated in the third person singular (er/sie/es ist ) rather than in the third person plural ( sie sind ). The answer I guess has to do with the German equivalent of the English impersonal 'it'. In other words, "Is (it) bad for them."