How to Pronounce 'AT, American English Pronunciation
The word 'AT' [ˈæt] as you may have noticed, most native speakers don't actually say the word 'AT' [ˈæt], most of the time it's more like [ət] or [ə] [ə], in both of these sounds we don't actually say [t], but we do move our tongue into a different position, that position is for the letter "d". If I was to begin a word with "d", "da", "da", you would see that the tongue comes down from being against the roof of the mouth, "Dad", however at the end of the word "AT" it moves up into that same position without actually making the [d] sound, [æ] now would be a common pronunciation for this word in conversation, however if the word it's not to be emphasized, it's not very important in the sentence, it´s more likely to come out [ə], [ə], like a schwa, or sometimes as a [ɪ] sound, but in both cases the tongue does come up to that position for the [d], an example, "I was at [ˈæt] the train station", "I was at [ˈæt] the train station", there I'm emphasizing 'AT' and it comes out with an [æ] vowel, however, perhaps "train station" is the more important part of the sentence, in that case I would say "I was at [ə] the train station", "I was at [ə] the train station", [ə], [ə], is then the pronunciation for the word 'AT' [ˈæt], in both cases though the [t] is not actually pronounced.