The spelling of "wast based" is often confusing because it contains a silent "e" at the end of "wast." This silent "e" is actually used to modify the pronunciation of the vowel "a" in "based." In IPA phonetic transcription, "wast" is pronounced as /wɑːst/, with the "a" pronounced as a long vowel sound. "Based" is pronounced as /beɪst/, with the "a" pronounced as a diphthong, or a combination of two vowel sounds. Together, the two words are pronounced as /wɑːst beɪst/.