es tan buena como

as good as

→ ser
phrase Rare #46,223
as good as Used in comparisons with a feminine singular adjective form; the adjective changes with the noun it describes.
SP: Tu idea es tan buena como la mía.
EN: Your idea is as good as mine.

Tu conjetura es tan buena como la mía.

Your guess is as good as mine.

La mía no es tan buena como la tuya.

Mine isn't as good as yours.

La comida no es tan buena como para venir a diario una semana entera.

The food isn't good enough to make me want to come every day for a whole week.

— Chainsaw Man - La película: El arco de Reze (2025)

Tu composición es tan buena como siempre.

Your composition is as good as ever.