"He is shorter than his father."
Translation:Ele é mais baixo do que o seu pai.
Why do you suspect that? I am not a native speaker, but I'm sure I've heard "baixo", rather than "curto", used to describe a short man . Based on my limited experience, I feel that although both "baixo" and "curto" can mean short, the former is used to describe height and the latter to describe length. I would talk about a man's height rather than his length.
In Portuguese, when we talk about height we use "baixo(a)" for short/shorter and "alto(a)" for tall/taller.
Shorter in portuguese is baixo or baixa (for a girl) and definitely not curto.
In Brazil, it is acceptable to say "ele é mais baixo que o seu pai". I don't know about other Portuguese speaking countries, it might be different, but I wouldn't advise the use of the word "curto" when talking about someone's height.
If we were having a conversation and I heard you say "ele é mais curto que o seu pai" I would laugh a little – not to hurt your feelings, of course, but because it sounds funny and odd at the same time.
Also, we usually use curto for things like objects and clothes. For example, if you want to say "Ana isn't shorter than me, but her dress is shorter". In Portuguese, you should say: "Ana não é mais baixa do que eu, mas o vestido dela é mais curto."
See what I did there? Ana is "baixa". The dress is "curto".
Hope it helps (:
In Brazil would be acceptable and to say "ele é mais baixo que seu pai". It means "he is shorter than his father. And as a native, I would indicate this sentence as the correct one.
I don't know about another Portuguese speaking country, but I am confident that saying "ele é mais curto que o seu pai" in Brazil would cause some confusion – if we were having a conversation I would laugh (not to hurt your feelings, of course, but because it sounds funny!
I would like to add that we generally use "curto" for things like objects or even clothes. For example: "Eu sou mais baixa que Ana, mas o vestido dela é mais curto que o meu".
For height, use "baixo(a) - short/shorter" and "alto(a) - tall/taller".