"This is the best gift!"
Translation:¡Este es el mejor regalo!
Gracias. Parece hay muchos excepciones a la regla que el adjetivo debe ser segundo https://www.spanishdict.com/guide/adjective-placement Qué molesto
Here's a good link to help with adjective placement, though you'll have to scroll down the page a little.
The quick synopsis is "BUENO/MAL" (good/bad) can go BEFORE or AFTER the noun without changing the mneaning of the sentence. But if it goes before a masculine noun, drop the "o".
Una chica mala. Una mala chica.
Un chico bueno. Un buen chico.
Some adjectives MUST GO BEFORE the noun...... -- MEJOR/PEOR (best/worst).
-- Adj. of quantity or order (five dogs, first lesson).
-- Quantatative adj. (demasiado/bastante/cada).
-- Possessive adj. (mi, tu, su, nuestro).
-- Adj. that describe inherent quality of an object. For example, "ice" by its very nature is cold. So if you say "cold ice" you would put frío before hielo.
Some adjectives CHANGE MEANING based on placement. If placed after the noun, it is a literal translation. If before the noun its a more abstract meaning.
Una amigo viejo = An old friend (physical age).
Una viejo amigo = An old friend (you've known them for a long time).
Un hombre grande = A big/large man.
Un gran hombre = A great man (well-respected).
El hombre pobre = The poor man (little money) El pobre hombre = The poor man (may be ill or in a bad situation ... you have sympathy for him).
There's more, but these will get you through most situations. See link at start of this post for a more thorough discussion.
Hope this helps.
Esto is neither masculine nor feminine. It is a neutral pronoun used (1) when you can't know the gender of the object: ¿Qué es esto? What is this?; or (2) when you are referring to a situation or set of circumstances: Esto es terrible. This is terrible.
Since we're saying "This (gift) is the best gift," we make "este" masculine to agree with "regalo."
It does mean the same thing overall, but isn't a trsnslation of the sentence Duo gave you which is probably why it didn't accept it. Rest assured, we would understand the meaning of your sentence if you used either in conversation. You could always report it and help Duo expand its answer queue.