Can you summarize John Keats' "On the Grasshopper and Cricket?"

This poem asserts the way in which "the poetry of earth" never ceases nor dies, as its song is carried on throughout the year by nature in its various guises. The title refers to the way in which the grasshopper and cricket are able to carry on this poetry even in the harshest or most inhospitable of weathers, when all other forms of nature are silent. The grasshopper is able to "take the lead / In summer luxury" in the heat of the summer when "birds are faint with teh hot sun." Likewise, in the depths of winter, when "the frost / Has wrought a silence" the cricket is able to sing out its poetry of earth from the stove. Both the cricket and the grasshopper therefore seem to operate as a pair, one taking over from the other, to ensure, as is repeated twice in this Romantic poem, that nature, or, "the poetry of earth" is never dead and there is always some example of the beauty of nature that characterises this form of poetry.

What was John Keats' intention in "On the Grasshopper and the Cricket"?

It is always difficult to guess what a writer actually meant to convey, especially if they are dead and we cannot ask them! However, what we can assess is what message a poem actually does convey, whether that was what the poet intended or not; hopefully, however, if the writer is skillful (as Keats was), we can imagine that they actually conveyed whatever message they intended.

In this poem, Keats conveys the beauty of even the smallest creatures, like the grasshopper or the cricket—two of nature's creations that human beings might be inclined to overlook because they are so small or seem so inconsequential. He draws our attention to them here. At the same time, Keats seems to be expressing wonder and awe at all of nature and "The Poetry of the earth" (line 1). Even when the birds tire, the grasshopper still sings his own song in the summer. Then, in winter, when the frost has made everything else seem silent, the cricket still sings. Though we do not always notice it, nature has a poetry that never stops, and Keats tries to draw our attention to its beauty.