Rule reminder
Final summary: anche (neutral addition) — persino/perfino (surprising) — addirittura (extreme) — neanche/nemmeno/neppure (not even) — mica (corrective negative, colloquial) — proprio (exact/really) — ben (intensifies numbers and adjectives) — pure (additive/permissive/concessive) — piano piano and other reduplications (expressive intensity).
Ho aspettato ___ un'ora intera davanti alla porta.