The correct spelling for the word typically indicated as "wast useful" is actually "was't useful." The contraction "was't" represents "was not," with the apostrophe indicating the missing letter "n." The pronunciation is [wɑznt ˈjuːsfl], with the stress on both syllables of "useful." This archaic construction was commonly used in Old English and is still used in some contemporary works to evoke a sense of historical or poetic language. However, it is not appropriate for everyday modern usage.
The phrase "wast useful" appears to be a combination of two words: "wast" and "useful".
The word "wast" is an archaic form of the word "was". It comes from the Old English word "wǣre", which means "was" or "were". Over time, this word underwent various changes and eventually became "was". However, "wast" continued to be used in English as a poetic or archaic form.
The word "useful" comes from the combination of "use" and the suffix "-ful". "Use" originated from the Old French word "user", which means "to employ" or "to use". It entered English around the 13th century. The suffix "-ful" is used to create adjectives and means "full of" or "characterized by".