"यह एक अच्छी किताब है।"

Translation: This is a good book.

[Fanuni]

Why can't this be, "This is one good book?"

[Zerenei]

That's also a correct translation.

[skiventist]

Why is it not अच्छा किताब? Is it because book is feminine?

[Zerenei]

Yep! Exactly, book is feminine in Hindi.

[Hadassah989835]

But why..?

[asemeniuc2006]

It just is, it's like a lot of other languages.

[ArnoNyhm2]

If this helps: try not to think of gramatical gender as an actual gender, but raher as an aspect of a word. Some words have a "feminine aspect", some have a "masculine aspect". Depending on the language (a lot of languages have grammatical genders), there might be more of these "aspects" and words might be seen differently, so with different grammatica genders (example: In Italian book is male and in German it has a neuter gender, that does not even exist in the other two languages).

[DharshnS]

oh that's ridiculous

[Mitaaksha]

This book is good?
Both literally mean the same.

[ChitraBala3]

I learned a lot