Why is it ¨Tengo un hermoso perro¨ and not ¨Tengo un perro hermoso¨ ?
Not being a native speaker, I can only speculate, but I get the impression that the dog’s beauty is not the essential piece of information, but rather that you have a dog which you find beautiful, whereas with “tengo un perro hermoso” you’re saying that you have a dog whose essential quality is its beauty.
(Good question to ask, reneladuree). I’m also not a native Spanish speaker, but doing some research… In Google Translate it spits out “Tengo un perro hermoso.” Which I know is perfectly fine. When I went to SpanishDict and searched ‘hermoso’ they have 28K examples using hermoso! I went through the first 10 pages and all of them had hermoso before the noun it described. So, I would say both ways (word order) are correct. I’ve noticed that with several other Spanish adjectives, seeing examples before and after the noun it describes.
This falls under the third point here: Spanish Adjectives Placement | SpanishDict
Also note that word order in Spanish in practice tends to be more flexible than how it is taught, and native speakers will often move words around to create small changes in nuance.
I am native speaker of spanish. “Tengo un hermoso perro” y “Tengo un perro hermoso” suenan igualmente naturales. “Hermoso” permite eso. Casa hermosa = Hermosa casa. No sucede así con todos los adjetivos, por ejemplo, “grande” no puede ir delante: ejemplo: “grande hija” está mal.