The correct spelling of the phrase "wast cautious" is actually "were cautious." The word "wast" is an archaic form of "was" in the past tense, while "were" is the plural form of "was." The pronunciation of "were cautious" can be transcribed as /wɜr ˈkɔʃəs/, with the stress on the first syllable of "cautious." This phrase describes a past state of being careful or wary, typically used as a directive or piece of advice.