How does vowel quantity affect the pace of English verse?

In English verse, vowel quantity—the duration of time required to pronounce a vowel—is a rhythmical feature that influences the pace of a line, though it does not function as a formal metrical system. While English is a strongly accentual language where stress patterns dictate metre, poets often use vowel length to modulate tempo and create expressive effects.12

Lines containing a higher concentration of long vowel sounds generally take longer to read or recite, effectively slowing the pace. Conversely, shorter vowel sounds can contribute to a quicker, lighter tempo. Because English lacks the fixed grammatical rules of quantity found in classical Greek and Latin, these effects are not precisely determined by the metre; rather, they are felt by the reader and can be lengthened or shortened at the poet's discretion to match the emotional tone of the work.134

While some poets have experimented with quantitative verse in English, it has rarely been successful because it ignores the natural, non-negotiable stress patterns of the language. Thus, in standard English prosody, quantity serves as a flexible, organic device that interacts with meaning and sound to shape the poem's overall rhythm.2413