A とも B とも JLPT N1 Very formal / literary

A tomo B tomo

Expresses two possibilities; 'either A or B', 'whether A or B'.

Formal, literary - one of several near-interchangeable "whether A or B" constructions; stylistic choice more than a formality ladder.

Formation

Noun + とも + Noun + とも (or sometimes Verb forms for each A, B)

The 'A とも B とも' grammar pattern indicates two possible scenarios. It can be translated as 'whether A or B' or 'either A or B'.

決断とも誤りとも、結果は時間が教えてくれるでしょう。

Whether it's a wise decision or a mistake, time will show the result.

Ketsudan tomo ayamari tomo, kekka wa jikan ga oshiete kureru deshou.
彼は父とも兄とも、もう何年も話していない。

He hasn't spoken to either his father or his brother in years.

Kare wa chichi tomo ani tomo, mou nannen mo hanashite inai.
彼女とも友達とも映画を見に行くつもりです。

I plan to go watch a movie either with my girlfriend or a friend.

Kanojo tomo tomodachi tomo eiga o mi ni iku tsumori desu.
このゲームには時間とも努力とも言えないほどの根気が必要です。

This game requires a kind of persistence beyond just time or effort.

Kono geemu ni wa jikan tomo doryoku tomo ienai hodo no konki ga hitsuyou desu.