この空いたカップをどこに捨てたらよいのか。

this (something or someone close to the speaker (including the speaker), or ideas expressed by the speaker)

to open (e.g. doors); to open (e.g. business, etc.); to be empty; to be vacant; to be available; to be free; to be open (e.g. neckline, etc.); to have been opened (of one's eyes, mouth, etc.); to come to an end; to open (one's eyes, mouth, etc.); to have a hole; to form a gap; to have an interval (between events)

cup (drinking vessel, measure, brassiere, prize, etc.)

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.

where; what place; how much (long, far); what extent

at (place, time); in; on; during; to (direction, state); toward; into; for (purpose); because of (reason); for; with; by; from; as (i.e. in the role of); per; in; for; a (e.g. "once a month"); and; in addition to; if; although

to throw away; to cast away; to dump; to discard; to abandon; to desert; to leave; to give up; to resign

good; excellent; fine; nice; pleasant; agreeable; sufficient (can be used to turn down an offer); ready; prepared; profitable (e.g. deal, business offer, etc.); beneficial; OK

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

indicates a question (sometimes rhetorical); or; whether or not; some- (e.g. something, someone); indicates doubt, uncertainty, etc.; emphatic prefix; suffix forming adjectives or adverbs; in that way