It can be. Many people do pronounce it that way. The correct BrE pronunciation is /ˈtjuːlɪp/, which sounds like 'tyulip'. There is a 'y' sound, known as a 'yod', before the 'u'. Other words such as 'tune', 'Tuesday, 'tube' and 'tutor' also have this pronunciation, where 'u' is pronounced as 'you'. This is the pronunciation you will find in dictionaries, and this is the one you will hear when well-spoken BrE speakers are enunciating carefully.* However, many people naturally combine the 't' and the 'y' sounds to create a 'ch' sound, so that 'tulip' sounds like 'chulip', 'Tuesday' like 'Chewsday', 'tube' like 'chube', and so on. This pronunciation is widespread and sounds quite normal to us. Although the 'ch' variant doesn't appear in the majority of dictionaries, most of us wouldn't even notice whether we're saying 'tyulip' or 'chulip'. *Note that the /ty/ issue is one of relatively few actual pronunciation differences between BrE and AmE English. [Most other differences are issues of accent, rather than actual differences in how you might see the word transcribed in a dictionary] . If you look in a good online dictionary, such as Macmillan, which has both pronunciations, you'll see that the AmE transcription is /ˈtuːlɪp/, without the 'y', pronounced 'toolip'. This phenomenon, known as 'yod-dropping', occurs in AmE before some consonants (particularly t, d and n) but not before others. AmE speakers don't miss out the 'y' in words such as 'fuse' and 'cute', for example. I hope that's helpful.