In surah kafiroon ayat 4 the word ana is read without the 2 second rule of elongating the naa.

Hi in surah kafiroon ayat 4 the word ana is read without the 2 second rule of elongating the naa. Apparently there are other places in the Quran where we don't elongate this ana. Can you tell me how we know this? As in the Arabic Quran normally this word would have a oval shape above it to indicate we don't stretch the na (noon fatah and alif)

Assalaam alaikum

The alif in the word  is one of the seven types of words in which the alif is pronounced when stopping on the word, but eliminated when continuing.

Please see the following link for more details: