お()年(とし)寄(よ)り() otoshiyoriには nihaできるだけ dekirudake親(しん)切(せつ) shinsetsuに niし shiなくてはいけません nakutehaikemasen。 You must be as kind to the elderly as possible. Literal Elderly [to-には] as-much-as-possible kind do-not [must-なくてはいけません]. ~なくてはいけません is the polite double-negative obligation: 'if one doesn't do X, it's not acceptable' = 'one must do X.' できるだけ adds intensity. The most emphatic version of the 'be kind to elders' theme. etiquette
お()年(とし)寄(よ)り() otoshiyoriには nihaできるだけ dekirudake親(しん)切(せつ) shinsetsuに niし shiなくてはいけません nakutehaikemasen。 You must be as kind to the elderly as possible. Literal Elderly [to-には] as-much-as-possible kind do-not [must-なくてはいけません]. ~なくてはいけません is the polite double-negative obligation: 'if one doesn't do X, it's not acceptable' = 'one must do X.' できるだけ adds intensity. The most emphatic version of the 'be kind to elders' theme. etiquette