"To Autumn" - Keats named his poem "To Autumn" as he wanted to celebrate the season.
"Seasons of mist" - Autumn is a season of change
"mellow fruitfulness"- the adjective 'mellow' suggests that autumn is calm and that the changes are not disruptive.
"Close bosom friend"- suggests that autumn works with summer to produce wonderful things.
"maturing sun"- the adjective "maturing" is used to describe the sun. It's suggesting that time is passing.
"Conspiring"- the verb suggests that autumn is quiet and secretive
"ripeness to the core"- suggests that autumn is the best season and represents the peak time in life.
"plump" and "o'erbrimm'd"- Keats uses adjectives such as "plump" and "o'erbrimm'd" to show the abundance of food that Autumn creates
"And still more"- Autumn is able to 'trick' nature and the wildlife into thinking that summer will never end.
"Who hath not seen thee oft amid thy store?"- Keats speaks directly to autumn. This suggests that autumn can clearly be seen anywhere.
"Thee sitting careless on a granary floor"- autumn is personified and this suggests that autumn works hard to make the changes in the season.
"Drows'd with the fume of poppies"- could imply that autumn is intoxicating and overwhelmingly beautiful
"Steady thy laden head across a brook;"- autumn needs to rest due to all the changes 'she' has made.
"Thou watchest the last oozing hours by hours."- Autumn has time to observe the changes it has made and enjoy the difference it has made to nature.
"Where are the songs of Spring?"- This implies that nature needs to be reassured, that it is a season which should be admired.
"Ay where are they?"- Due to the changes autumn has made, spring has been forgotten; implies that autumn is powerful.
"The red-beast"- suggests that autumn has done its job and winter is on its way.
"And gathering swallows twitter in the skies."- the last line could suggest that Keats is ready for death and to 'move on' just as the 'swallows' are 'gathering' to move on to warmer climates.
In the last stanza, Keats uses language associated with death such as 'soft-dying', 'wailful' and 'mourn'. This could imply that autumn is dying and that Keats's own life is coming to an end.