At 1400, they add in the thorn "þ". If you don't know that's supposed to be "th", you'll get stuck there.

No, not that. The endings are different, the verbs are substantially different. AFAIK invention of printing had generally stabilizing effect on English.

It is not that I am incapable to understand old English, it is that 1600 is dramatically closer to modern than 1400 one; I think someone from 1600 would be able to converse at 2026 UK farmers market with little problems too; someone from 1400 would be far more challenged.

	▲	dhosek 3 hours ago \| parent \| next [-]
		Not to mention that there are pockets of English speakers in Great Britain whose everyday speech isn’t very far from 17th century English. The hypothetical time traveler might be asked, “So you’re from Yorkshire then, are you?”
	▲	adrian_b 2 hours ago \| parent \| prev [-]
		The invention of printing had a stabilizing effect on all languages, at least of their written form, because for some languages, especially for English, the pronunciation has diverged later from the written form, but the latter was not changed to follow the pronunciation. I have read many printed books from the range 1450 to 1900, in several European languages. In all of them the languages are much easier to understand than those of the earlier manuscripts.