2006(1) What is the rule for 'how long' questions pertaining to time - is the preposition needed at the end of the question or not, For practical purposes "for" is not really needed, but there is a difference in meaning with and without "for".
Or...how long do I need to cook the rice for? This is very clear that you want to know for how many minutes the rice should be on the hot stove (or in the rice cooker).
e.g...How long do I need to cook the rice? This sentence would usually be taken to have the same meaning as the one above, but it can also mean 'How much time will I need to spend cooking the rice?' This can include the time heating up the stove, putting water and rice into the pot, etc, and time spent actually cooking the rice.
So if you want to very clearly have the first meaning, you should use "for".
(2) What is the rule for using 'for' in questions? Does it come at the beginning, end or not at all, "for" should be used.
e.g 'For what do you use a recipe?'
or 'What do you use a recipe for?' "
I was told that they used to teach the concept that a preposition should not end a sentence - Prepositons can and very commonly do end sentences. Don't follow that old teaching.
What do you need a hundred dollars for?
I don't know which table to put the flowers on. .
(3) What is the rule for using 'from' in questions? Beginning, middle or end? For example, 'From where do people come to watch the game?' or 'Where do people come from to watch the game?' or
'Where do people come to watch the game from?' This sentence is wrong if you want to have the meaning of the first two sentences. This question is asking 'exactly where in or near the stadium' do people watch the game from. While this question would rarely if ever be asked, that's what the grammar used in that sentence means.
Any help is greatly appreciated.