The primary metrical pattern in Frost is the primary metrical pattern in English poetry, which is to say blank verse or unrhymed iambic pentameter.

弗罗斯特基本的诗歌韵律,是英国诗歌的基本韵律，也就是无韵诗或不押韵的五音部抑扬格。

耶鲁公开课 - 现代诗歌课程节选

Free verse is non-metrical poetry, another thing altogether.

自由诗体是无韵律的诗，总的来说是另一种诗体。

耶鲁公开课 - 现代诗歌课程节选