Some written forms have distinct pronunciations in continuous reading and in stopping. The word «أَنَا» has an alif written after its nun. In its ordinary prescribed treatment, the final alif is not sounded as an independent long vowel when the word is joined to what follows, but it is pronounced when the word is properly stopped upon.
Joining: the last written alif of «أَنَا» does not receive the independent length used in the pause.
Stopping: the alif is heard at the end of the stopped word.
The difference follows transmitted reading rules, not an assumption from spelling alone. A reciter must apply the rules of pausing at a stop and the rules of joining in continuous recitation, rather than forcing one pronunciation on both states.