あなたはここで待ってさえいればいいのです。

you (referring to someone of equal or lower status); dear (what a wife calls a husband)

topic marker particle; indicates contrast with another option (stated or unstated); adds emphasis

here (place physically close to the speaker, place pointed by the speaker while explaining); this place; these last (followed by a duration noun and a past sentence: time period before the present time of the speaker); these next ... (followed by a duration noun and a non past sentence: time period after the present time of the speaker); the next ...

indicates location of action; at; in; indicates time of action; indicates means of action; cause of effect; by; and then; so; indicates continuing action; indicates certainty, emphasis, etc.

to wait; to await; to look forward to; to anticipate; to depend on; to need

even; if only; if just; as long as; the only thing needed

to need; to want

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

be; is