いつしか (translations)→ eventually inevitably now place suddenly
いつのまにか (translations)→ somehow
いよいよ (translations)→ about close even ever finally great greatly more really rich so steadily still very
しだいに (translations)→ grow increased increasingly
すこしずつ (translations)→ cautiously slowly
そのうちに (translations)→ presently preserve shortly someday sometime soon then until
そろそろ (translations)→ almost gently high nearly slow
だんだん (translations)→ begin constantly
だんだんと (translations)→ indirectly modest
どんどん (translations)→ aggressively all dramatically eagerly fair fast good keep quickly rapidly
やがて (translations)→ afterward later long long-run momentarily till ultimately while
ゆっくりと (translations)→ carefully deliberately distantly leisurely pondrously restful slo-mo unhurriedly
ようやく (translations)→ barely before fully laboriously last only rare reach reluctantly scarcely
次第に (translations)→ down little progressively steady
徐々に (translations)→ adaptively incrementally near
少しずつ (translations)→ imperceptibly