if you want to say it properly it should be Hekham (you can't use ''ha'' before the vowl ''a'' like in ham), but it actually very common and natural to say Haham. If you watch israeli movies from the 70's and 80's you would hear tham say Heham more often.
And would chalav cham be correct either to say warm milk? And could that same sentence mean '(a) milk is warm'?
If only the noun has the definate article and not the adjective the translation uses the verb 'to be'. החלב חם - 'the milk IS hot'. If the article is on both noun and adjective then the adjective describes the noun directly. החלב החם 'the hot milk'. If there isn't a definate article on either noun or adjective, it could be either. חלב חם 'milk is hot' or 'hot milk'. You use the context to determine the meaning.
I don't think this would be used to say "milk is hot". Rather "חלב הוא חם" or "חלב זה חם".
It's החלב חם because Hebrew requires the adjective to have a definite article attached to it as well as the noun.
what is the system for determining which vowel sounds apply to which words. Looking at this prima facie, I'm unable to determine that the vowel takes the 'a' form. I only know by listening to the speaker but my intuition tells me there's an easier way than rote memory for determining vowel sounds. Can anyone advise?
There is no such system. Classical text, such as the Hebrew Bible, as well as modern poetry, use a system called Nikkud which has symbols for vowels that are seperate from the letters. For modern writing, however, you just need to get used to the language. Don't worry, soon enough you'll recognise anough words and develop an intuition about it!
I am learning to read hebrew for sounds not words, there are dots under the letters that symbolize vowels. Once we have learned that part of the torah with vowels we have to memorize without the vowels. it is very hard to not use vowels after you have been taught for 4 years to read with vowels.
I hope that answers your question
They are homographs, just like any other. You get to know them better through intensive practice.
It is said that people process words as a whole. Just learn them as units, together with the way they're pronounced.
So why is החלב חם "the milk is hot", but לחם חם is "hot bread" only? Lack of the article?
Hebrew does not use the "to be" verb. But when translating to English, you add it (not "the milk hot")
is the "ח" in "חם" chet? but why does it still sound like /ham/ to me instead of /kham/?
Does חם mean specifically 'hot' or also cover 'warm'? How would you say 'the milk is warm'?
I typed "the milk is hot" but got it wrong because I didn't type in hebrew. But nowhere was I asked to type in hebrew.