The phrase "hadst a go" is an archaic expression for "have or had given it a try". Its pronunciation is [hædst ə ɡəʊ], with the stress on the first syllable of "hadst". The "st" at the end of "hadst" indicates that this word is in the past tense, and it is often associated with Shakespearean English. While this spelling may not be commonly used today, it is important to understand its historical significance and its place within the English language's evolution.