The pattern, i.e. literary devices, of William Wordsworth's "Lines Composed a Few Miles Above Tintern Abbey" contributes to the tone of the poem in several ways.
The poem is written in "blank verse", or unrhymed iambic pentameter, that gives a fluid and meditative tone, as if we are hearing Wordsworths's own reflections as they pass through his stream of consciousness.
The theme of return and melancholy is enhanced by the repeated references to the passing of time which structure the poem. Wordsworth's own journey from innocent joy in nature to loss of innocence to recapturing a deeper joy of memory is recapitulated in the structure of the poem, which uses memory themes to move from melancholy to the epiphany and joyous tone in the conclusion:
... Nor, perchance--
If I should be where I no more can hear
Thy voice, nor catch from thy wild eyes these gleams
Of past existence--wilt thou then forget
That on the banks of this delightful stream
We stood together; and that I, so long
A worshipper of Nature, hither came
Unwearied in that service: rather say
With warmer love--oh! with far deeper zeal
Of holier love.