The meter in lines 9 to 13 changes from one line to the next. Line 9 begins with an anapest, a grouping of three syllables ("What is all") in which the third syllable is emphasized. The rest of the line is iambic, and consists of three iambs. An iamb is a pair of syllables in which the second syllable is stressed. Thus the rest of line 9 reads: "this juice and all this joy." The anapestic meter at the beginning of the line creates an initially slow rhythm, and the iambic meter which follows then speeds up the rhythm.
Line 10 is also written in iambic meter, but finishes with an unfinished iamb. The line thus reads: "A strain of the earth's sweet being in the beginning." The final syllable, "ing," is the first syllable of an unfinished iamb. Lines 12 and 13 are also written in an unfinished iambic meter.
Line 14 begins with a single emphasized syllable ("Most") which is then followed by a dactyl, which is a grouping of three syllables ("O maid's child") whereby the first syllable is emphasized. The rest of the line is written in iambic meter, and reads thus: "thy choice and worthy the winning."
The irregularity of the meter in the second stanza perhaps is meant to echo the freedom and spontaneity of the natural world in the season of Spring. The iambic meter, which is the dominant meter in the stanza, lends to the poem a bouncy, musical tone, echoing the joyfulness of the season. By writing several lines within the second stanza in an unfinished meter, Hopkins creates a suggestion of uncertainty, or, put another way, a lack of resolution. This, combined with the fact that the pace of the lines slows down in places, with single anapests or dactyls, might reflect the speaker's uncertainty as to how long the beauty and innocence of spring might last. Indeed, in lines 11 and 12, the speaker entreats the reader to enjoy Spring while he or she can, "before it cloy, / Before it cloud."