One of the most famous Middle English poems is a song, written in or near Reading around the middle of the thirteenth century — say, 1240–60 — a bit more than a century before Chaucer started his career. The text appears in British Library MS Harley 978, fol. 11v. I’ve consulted images of the original and compared them to various published transcriptions.
Things that can’t be explained in a word or two get fuller treatment in the “Notes” section at the bottom of the text.
|Sumer is icumen in||has come|
|Lhude sing cuccu||loudly|
|and bloweþ med||mead bloweth (the meadow blooms)|
|and springþ þe wde nu||sprouts — forest|
|Awe bleteþ after lomb||ewe — bleateth|
|lhouþ after calue cu||loweth — cow|
|murie sing cuccu||merry|
|Wel singes þu cuccu||thou|
|ne swik þu nauer nu||stop — thou — now|
|Sing cuccu nu · Sing cuccu.|
|Sing cuccu · Sing cuccu nu.|