For a learner, it can only at any time helpful to suit your needs to differentiate /ʊ/ and /u:/, not /ʊ/ and /u/, and you'll do this by length.It is far from absolutely in contrast to "sh"s in "dishwasher", but you'll likely be recognized by your pronunciation of the just after a decade of follow /wink/. Let us contact this one "mouthy" pronuncia