Thee and thou are still occasionally heard in association with verbs in the imperative or subjunctive (itself almost but not quite extinct). Be thou...were thee...etc. Yow and Ye are still common personal pronouns in some dialects, the first in west midlands speech, the latter in Northern Ireland country areas. Y and TH are often interchangeable in dialect. For example, Yon and Thon. People tend to form their speech, not in individual words, but in word strings. Sometimes, an archaic phrase lingers on for use in to convey particular contexts.