We don't know who 'her' is - perhaps love or nature personified, together with 'summer evening' creating a calm, beautiful and romantic atmosphere. On this evening, the poet finds 'A little boat', 'little' suggesting its beauty and perfection, while later on this will show its fragility. Specificity is created in the natural world in these lines with 'willow tree' and 'rocky cave' creating a clear sense of the image. The boat is personified as 'her', perhaps a metaphor for the human imagination or spirit, which is originally tied to nature (willow tree) and then is used to explore nature. In these lines we can see the boat as graceful, 'unloosed' showing her new freedom, as Wordsworth almost starts a confrontation with nature by unchaining the boat. Further in the text this is supported by the fact that 'It was an act of stealth.' Pace is created at the start of the lines by using verbs, adverbs and prepositions, emphasising how he pushes the boat from the shore suddenly. The caesura after 'shore' almost splits the text, changing from description of the act to his adult thoughts upon it.
'troubled pleasure' shows that his crime nevertheless pleases him - he enjoys having control and power over something he is not supposed to have. Subtle inversions in the next lines both disconcert the reader and are supposed to reflect the conflict inside him. 'Mountain-echoes' again subtly personifies nature, showing the boy is surrounded by the overwhelming voice of the natural world. Wordsworth then uses enjambment to not allow us to stop, mirroring the overwhelming emotions and beauty of the natural world. 'Small circles glittering idly in the moon' and 'sparkling light' creates a semantic field of light, as the world 'melted all into one track/Of sparkling light'. The natural world coalesces into one exceptionally beautiful thing, leading Wordsworth on a 'track' to his moment of truth.
Caesura again disrupts Wordsworth from the perfection of nature, 'proud of his skill' shows his arrogance (and hubris), 'reach a chosen point' reflects on his great determination and unceasing struggle to get what he wants. 'Unswerving line' shows us the great potency and stability of the lines of the earth, the life of a human is temporary against the 'fixed' nature of the natural world. 'I fixed my view upon the summit of a craggy ridge', 'fixed' shows Wordsworth's determination and concentration, the 'summit' then bringing the revelation which is about the come. 'Summit' also suggests the triumphant top of the mountain, suggesting the great power of nature. 'Craggy ridge' uses consonance to show the roughness of nature.
'The horizon's utmost boundary' almost contradicts the power of nature, suggesting the even nature has somewhere it cannot get. Wordsworth then looks beyond this to the 'stars and the grey sky', showing him looking to the limitless expanse of the universe. 'She was an elfin pinnance' means she was an elvish boat, again linking to the mystical quality of the natural world, and the boat which brings him through it.
'I dipped my oars' shows the narrator's gentle motions, and 'as I rose upon the stroke' uses assonance to create beauty, while the simile comparing the boat to a swan creates an image of perfection, whilst nevertheless reminding us that man can only imitate the beauty and perfection of nature. Suddenly, a 'huge peak' arises from beyond the crag, 'black and huge' using simple and monosyllabic words to show the sinistry of the mountain, with 'power' instinctual to the mountain. 'Voluntary' shows a juxtaposition - nature already has power versus man who must strive for it. 'Upreared its head' personifies the mountain, showing the bestial quality of nature - which may be violent and harmful as much as it may be peaceful and beautiful. Caesura follows this, cutting off and disrupting this section from the following one.
'Dipped' turns to 'struck and struck again', showing the impact nature has had on the boy - he must almost fight back against it. 'the grim shape/Towered up between me and the stars', showing how the foreboding shape of the mountain cuts the boy off from all light and beauty, towering over him like a castle with violent and war-like connotations. With ''a purpose of its own [...] strode after me' suggests the nature is trying to stop him from abusing its beauty.
Again the narrator uses his oars to convey his emotions, 'trembling oars' showing his fear, vulnerability and newfound respect of nature. Now it is not simply the boat which is stolen, but the 'way' as well, showing how Wordsworth must be stealthy to hide from nature and return safely home. Sibilance here creates the sound of the boat gliding through the water. 'Silent' creates an atmosphere of fear and suspense. He leaves the boat behind, going 'through the meadows', whose peaceful and homely qualities juxtapose the terrifying mountain of before, and the narrator's own 'grave/And serious mood', having given the boat back to nature. 'Grave' suggests both seriousness and the reminder of the narrator's mortality versus immortal nature.
It took him 'many days' to fully understand what he had seen, showing again the power of nature. 'undetermined sense/Of unknown modes of being' shows his complete confusion, which no 'dim' light can illuminate. Nature, it seems, is a completely different kind of being to man. Again, there is darkness but now in his mind rather than in the outside world, showing his troubled confusion. 'o'er my thoughts/There hung a darkness', showing the change in his perspective of the world, darkness hanging like a curtain over his view. In his eyes 'No familiar shapes/Remained', using very grim images of isolated location, and list forms, to show that none of the beauty of the world is now clear to him. Instead all he can see are the extremes of 'huge and mighty forms, that do not live/Like living men', repetition of the verb 'live' suggesting his difficulty in understanding how nature even exists. He is pursued and almost haunted by nature.