Final answer:
The bolded phrases in the excerpts use metaphor and imagery to discuss themes like the passage of time, beauty's transience, and the inevitability of decay and mortality, showing how language can capture the depth of the human condition.
Step-by-step explanation:
The bolded phrases from the excerpts of Shakespeare and other poets use vivid imagery and metaphors to convey themes of time, decay, and the ephemeral nature of life. For instance, 'When forty winters shall besiege thy brow' from Sonnet 2 by William Shakespeare suggests the passage of time and its effects on human beauty. Similarly, the expression 'And summer's lease hath all too short a date' from Sonnet 18 also by Shakespeare, conveys the transient quality of summer, paralleling the fleeting nature of youth and beauty.
In the context of literary analysis, these expressions demonstrate how poets use language to explore deeper truths about human existence and the relentless march of time. Moreover, phrases like 'Trace your grave, and build' and 'Shrink to your cellars, holes and cells' portray the inevitability of mortality and the diminishing arenas of human life as age advances. Poets hence encapsulate the universal human experience using metaphorical language that transcends the literal meaning of the words.