Could you say 'fica no portão' instead?
"Ficar" means something for a long time..... but the sentence told that the dog was there at that moment.... ;)
I wrote: "O cachoro está ao portão", why is this wrong?
It's not, "ao" and "no" have the same meaning.
Welcome (and I forgot to tell you, not always... but in this case you could use)
I thought so! Thank you again for the input...