友達がここにいないのでがっかりだ。

friend; companion

indicates sentence subject (occasionally object); indicates possessive (esp. in literary expressions); but; however; still; and

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 ...

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 need; to want

that being the case; because of ...; the reason is ....; given that...

feel disappointed; dejected; lose heart; feel emotionally drained; feel let down

be; is; indicates past or completed action; indicates light imperative