A minimal pair is a pair of words that differ only in one sound, which demonstrates that a certain pair of sounds is contrastive.

In English, [pʰ] and [b] form a minimal pair (bat[bæt] and pat[pʰæt]) and are contrastive, but[pʰ] and [p] are not. In Korean, [p], [pʰ], and [p͈] are contrastive because they form minimal pairs: 불[pul], 풀[pʰul], and 뿔[p͈ul].