何をそんなに悲しんでいるの。

what; how many; you-know-what; that; whatsit; what's the expression; what do you call them; what?; hey!

indicates direct object of action; indicates subject of causative expression; indicates an area traversed; indicates time (period) over which action takes place; indicates point of departure or separation of action; indicates object of desire, like, hate, etc.

so much; so; like that

to be sad; to mourn for; to regret

indicates possessive; nominalizes verbs and adjectives; substitutes for "ga" in subordinate phrases; (at sentence-end, falling tone) indicates a confident conclusion; (at sentence-end) indicates emotional emphasis; (at sentence-end, rising tone) indicates question