Nasalization and height increase noticeably with time during the production of a single nasal vowel in BP in those cases that are written with nasal consonants ⟨m n⟩, so that may be realized as or . This creates a significant difference between the realizations of ⟨am⟩ and ⟨ã⟩ for some speakers: compare for instance "ranço real" (PT) or (BR) ('royal rancidness') and "rã surreal" (PT) or (BR) ('surreal frog'). (Here [ɰ̃] means a velar nasal approximant.) At the end of a word ⟨em⟩ is always pronounced with a clear nasal palatal approximant (see below). Whenever a nasal vowel is pronounced with a nasal coda (approximant or occlusive) the (phonetic) nasalization of the vowel itself is optional.