The first step is to decide whether the extract sounds complete or not. If the extract sounds completed, it will either be a perfect or plagal cadence. The chord progression of a perfect cadence is V-I. This cadence sounds fully complete. The plagal cadence has a chord progression of IV-I. This cadence is usually used in religious pieces such as oratorios and hymns.If the piece doesn't sound finished, it will either be an imperfect cadence or an interrupted cadence. The imperfect cadence has a chord progression of (any chord)- V. This cadence sounds unresolved. If you can imagine it resolving to the tonic (I) and it sounding finished, it is most likely going to be an imperfect chord. The interrupted chord has a chord progression V-VI. This cadence sounds as if it is about to resolve onto the tonic (like a perfect cadence) but ends up on the VI chord.