"I wear a coat until I am warm."
Translation:Ik draag een jas, totdat ik het warm heb.
Not really. Just that "het warm hebben" means "to be warm" and "het koud hebben" means "to be cold".
Is it compulsory to say "I have it warm/I have the warmth", or could one say "...totdat ik warm ben" ?
"totdat ik warm ben" works too. But as a native speaker I'd personally prefer ''totdat ik het warm heb'' or ''totdat ik opgewarmd (warmed up) ben"
Apparently it has something to do with loosely being: 'having a feeling'. I'm not native, but I read it on one of the other posts a long time ago. I can't remember the exact explanation but I have just trained myself to remember that phrase
Normally, it would be 'ik heb het warm' -- subject, verb (2nd), rest of verb phrase (het warm hebben), but because it's placed in a subordinate clause, we have to use the subordinate clause word order, where the verb goes to the end. And so it becomes '...totdat [subordinating conjunction] ik [subject] het warm [rest of verb phrase] heb [verb last]'.
Hope that helps.