しきりに (translations)→ bitterly busily conjecture copiously desperately eagerly endlessly fluently frequently furiously hard imperiously incessantly insistently intently keep much often rapid steadfastly terribly urge urgent urgently variously
つくづく (translations)→ appreciatively closely completely death dreadfully fully genuinely somehow strongly surely thoroughly utterly
ひたすら (translations)→ all anxiously avidly doggedly earnest just literally stolidly undeviatingly unflagging
まじまじと (translations)→ blankly carefully curiously fixedly silently soberly speculatively steadily thoughtfully
まじめくさって (translations)→ gravely stern
ジッと (translations)→ resignedly
懸命に (translations)→ busy contrive frantically judiciously resolutely tightly tirelessly
真顔で (translations)→ dryly frankly serious seriously solemnly
力をこめて (translations)→ emphatically firmly lustily vehemently vigorously