English grammar; ‘a’, and ‘an’?

Question

I take an online course and the instructor used a software program to review my grammar. I used the words “an FTP program” in a sentence and the software corrected me. I think I am generally aware of the rules of ‘a’, and ‘an’; and constants, and vowels (e.g.: a bat, an encyclopedia). However the word FTP is pronounced ef-tee-pee, so I thought the use of the word ‘an’ was the correct choice because it is *pronounced* as if it begins with a vowel. Am I wrong? Is it the spelling or the pronunciation that counts with 'a', and 'an'?

Answer 1

It is clear that software was the source of this correction. (But it is very sad that the instructor didn't notice the software's error.)
If software is poorly written it fails to recognize when an acronym is pronouced as a string of letters. (Not always the case. Some acronyms are pronounced as a word. Ex: "FLIR" stands for forward-looking infrared. It is often pronounced "fleer" rather than "ef-el-eye-are".)

You are correct. The a/an choice exists to assist human pronunciation.

It has gotten fuzzy over the years because humans are inconsistant. Some style sheets say to put "an" in front of words like "human" because some dialects of English don't pronounce the "h". So you can imagine the software programing problem of getting the grammar checker to make decisions based on how the reader is most likely to read the words aloud.

You have my sympathy.
At least the "Learn English" network agrees with us. See link below.