Accent Reduction
Can and Can’t
In British English, we tend to differentiate Can and Can’t with very distinct vowel sounds, especially in MRP Modern Received Pronunciation (a neutral well-spoken English accent).
Many of my clients, when speaking to UK natives, find it difficult to make themselves understood when using the negative contraction of ”can” ( = can’t) as they use the same vowel /a/ as in CAN. This problem occurs so often that they resort to saying “cannot” not to cause confusion. Using “cannot” in spoken English sounds quite heavy and clumsy. So instead, I’d recommend distinguishing “can’t” with the long /a:/ as in CAR as opposed to the /a/ as in CAT.