"Hoy es un día bello."
Translation:Today is a pretty day.
'Today is a beautiful day' would be a more normal statement. Days aren't described as pretty
As support for your opinion, note that if you mouse over "bello" in the exercise, one of the three translations given is "beautiful". "Pretty" is not given as an option.
That's nothing to go by. The hover options are notoriously unreliable.
Merriam Wester's dictionary lists pretty as an adverb, adjective and even a verb so it must be valid. Neither have I heard it used as adjective to "day" as in the suggested answer but it is often used as an adverb as follows: A pretty nice day. A pretty bad day. etc. The most important thing I learned from the MW dictionary is that the word "pretty" has very different meanings depending on the part of speech it is assigned to.
I suppose it's possible that there are other countries that speak English in which this is an extremely common construction. Americans and Canadians would never put "petrol" in a car; nevertheless, it's proper and grammatical.
I've read all the above comments and I would like to add mine. I'm a native (UK) English speaker. I would never say "What a pretty day", but I would say "What a beautiful day". I looked up 'bello/a' in the dictionary and 'pretty' is not one of the words offered as a translation, but 'fine' and 'fair' are. These are both words that are often used to describe 'the day' in English, which are usually indicating the kind of weather we are currently having, therefore the nuance is on what we are feeling, or experiencing about the day. Pretty is more usually used to describe something one is seeing, like a snow-covered landscape, or a garden filled with flowers.
I prefer beautiful. The sentence: What a beautiful day, sounds like music.
Can any native Spanish speakers comment on difference in usage between bello/bella and bonito/bonita? Does usage very based on context, on the country, or both?
A beautiful or lovely day is normally used A pretty day is more theatrical