I've kind of answered this question already here and here so your answer really depends on where your farmstead is.

As I mentioned in those other threads, the consensus of current DNA evidence suggests that the "fall" of Britannia wasn't exactly the terrible trauma suggested by Gildas and Procopius with the mass replacement of the native Britons with the English, but nor was it purely a conquest of elites. The process of Anglicisation seems to have been a steady process, probably with Anglo-Saxon villages cropping up intermingled with earlier Briton settlements, with intermixing occuring faster and to a greater extent the further east you go. The language likewise takes at least a century to spread and adapt, with central England, and then Western England likely being bilingual for some time, and the early Germanic picking up significant Brythonic grammatical structures and pronunciation during its growth into Old English.

So if your setting is somewhere like Kent, your Britons are likely to speak Old English, possibly with some Brythonic loanwords or hangovers. They're likely to live in mixed settlements as equals, and use more English material culture. If they're somewhere like Wiltshire or Dorset, in the nascent Kingdom of Wessex, they're probably bilingual, speaking Brythonic to each other or traders from the West, and English to people from the East, and to their lord and his retinue, who will be Anglo-Saxon.

In the West, somewhere like the lands of the Magonsæte in modern day Worcestershire, they'd probably speak English only as a second language, and still use predominantly British material culture, although English designs would be growing steadily more prevalent. Their lord would probably still be Brythonic, and actually, given the political function of the Mercian hegemony which eventually established control over the Magonsæte, may have actually continued being Brythonic and potentially even speaking some Brythonic into the ninth or even tenth centuries.