「祖父母は同じマンションに四十年住んでて、ご近所さんの名前を全員知ってるんだ。」を英語で言うと
英語では
My grandparents have lived in the same apartment building for forty years and know every neighbor by name.
英語では
My grandparents have lived in the same apartment building for forty years and know every neighbor by name.