In "The Road Not Taken," the four stanzas are five lines long with a rhyming scheme of ABAAB.
Two roads diverged in a yellow wood, (A)
And sorry I could not travel both (B)
And be one traveler, long I stood (A)
And looked down one as far as I could (A)
To where it bent in the undergrowth; (B)
Each line, if Frost kept to the common iambic pentameter, would be five "feet" long; however, Frost writes this poem with four "feet" or tetrameter. (Feet or units in poetry contain stressed and unstressed syllables, as in the iambic da-Dum.)
If the first stanza of Frost's poem were broken up into units or feet, it would look like this -
Two roads/ diverged/ in a yel/ low wood, (A)
And sor/ ry I /could not tra/ vel both (B)
And be/ one tra/veler, long /I stood (A)
And looked/ down one/ as far /as I could (A)
To where/ it bent /in the un/dergrowth; (B)
Frost is quoted as saying, "There are only two meters "strict and loose iambic." In the lines of this poem, we see what he means by loose iambic meter."
Meter in English poems is usually one of five types - Iambic, Trochee, Spondee, Anapest, or Dactyl. Iambic consists of an unstressed syllable followed by a stress syllable. Trochee is the opposite, beginning with a stressed syllable followed by an unstressed syllable. In spondee, both syllables are accented. Anapest starts with two unstressed syllables followed by one stressed syllable. A dactyl is the opposite of an anapest with one stressed syllable followed by two unstressed syllables.