机の上にファンレターが山と積まれていた。

desk

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

fan; fun

letter

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

mountain; hill; mine (e.g. coal mine); heap; pile; crown (of a hat); thread (of a screw); tread (of a tire); protruding part of an object; climax; peak; critical point; guess; speculation; criminal case; crime; mountain climbing; mountaineering; festival float (esp. one mounted with a decorative halberd); wall; wall tile; temple; temple grounds; wild

if; when; and; with; particle used for quoting (with speech, thoughts, etc.); quoting particle; promoted pawn; indicates question (sentence end)

to pile up; to stack; to load (car, ship, etc.); to pack; to acquire; to accumulate