Should've is a contracted form meaning 'should have.' It functions as an auxiliary + verb combination indicating a past expectation or probability. In casual speech, it often blends to a syllabic, compressed form, reducing to a single stressed syllable in many contexts; its pronunciation relies on linking and elision to fit speech tempo while preserving the target vowel quality of /ʃɪ/ or /ʃə/ plus an implied /v/ sound. It is commonly used in informal writing and speech.
Full pronunciation guide
