The spelling "hadst the advantage" is an archaic form of the phrase "had the advantage," commonly used in Old English texts. Its pronunciation is hædst ði ədˈvæntɪdʒ with the phonetic transcription indicating that the "a" is pronounced as in "cat," the "d" is pronounced like "th" in "this," the "i" as in "hit," and the "g" as in "go." The form "hadst" indicates the second-person singular past form of "have," and "advantage" means a favorable position or opportunity.