Blank verse is a poetic form that uses unrhymed lines of ten syllables each, with an alternating pattern of unstressed and stressed syllables. It's often referred to as "iambic pentameter" because each line has five "iambs", which are metrical feet consisting of an unstressed syllable followed by a stressed syllable.
If you're referring to lines that deviate from the strict iambic pentameter rhythm, it's important to note that even within blank verse, some variation is allowed. This is because blank verse aims for naturalness and conversational flow.
Examples of slight deviations in the poem:
* Line breaks: The poem might sometimes break a sentence across lines, creating a slight shift in the rhythm.
* Enjambment: This is when a sentence continues onto the next line without punctuation, often adding a sense of momentum.
* Caesura: This is a pause within a line, which can also affect the rhythm.
Overall, while there might be minor deviations in rhythm, "Lines Composed a Few Miles Above Tintern Abbey" is still considered blank verse.
To be sure, it would be helpful if you could provide the specific lines you're referring to. This would allow for a more accurate analysis of their metrical structure.