T-glottalization
In English phonology, t-glottalization (also t-glottalisation) or t-glottalling is a sound change in certain English dialects and accents, particularly in the United Kingdom, that causes the phoneme to be pronounced as the glottal stop [ʔ] in certain positions. It is never universal, especially in careful speech, and it most often alternates with other allophones of /t/ such as , [tʰ], [tⁿ] (before a nasal), [tˡ] (before a lateral), or [ɾ].