In British English, we do this a lot with ‘u’ sounds. For example, in London we take the Tube, which Americans pronounce ‘toob’ and we pronounce ‘choob’. Strangely enough, almost all English speakers do this with the word ‘train’ and other ‘tr’ words without even knowing it: the first sound is not ‘t’, it’s ‘ch’.

Both British and American English speakers do something similar with ‘s’. For example, ‘issue’ is pronounced ‘ishoo’ except by people with very strong RP accents (that is, posh people), who say ‘iss-yoo’.

It’s a similar phenomenon to the ‘c’ before ‘i’ and ‘e’ transforming into ‘s’, e.g., in ‘science’, ‘ceiling’ and probably hundreds of other words (‘cœliac’ is a particular favourite). Italians do something similar, but they make it ‘ch’ as in ‘ciao’.

Brazilian Portuguese speakers change ‘t’ and ‘d’ to ‘ch’ and ‘j’ respectively before ‘i’ and ‘e’ sounds. For example, the word ‘de’ meaning ‘of/from’ is pronounced more like ‘juh’. In Portugal, though, they use a hard ‘d’.

So, in summary, ‘e/i’ and ‘u’ sounds all have a tendency to transform the preceding consonant, especially if that consonant is ‘t’, ‘s’, ‘c/k’ or ‘d’, more rarely with ‘j’ and ‘z’ and sometimes with ‘b’. If and how they change varies by language and dialect.

(Note: I’d have done this with IPA but I’m not sure about Lemmy’s support for it and I didn’t want to type it all out and have it be a load of non-loading characters, hence my approximations of the pronunciations. Apologies to any linguists out there!)