"I want to share this umbrella."
Translation:Tôi muốn chia sẻ cái ô này.
They are focusing on using Northern terms more even though most Vietnamese speakers are Southerners. It's complicated since although the Hanoi dialect is considered "standard", it's only politically motivated. Obviously prior to 1975 Vietnam had 2 standards: Hanoian and Saigonese.
đây is a noun and này is an adjective.
English is fairly rare as a language where they both take the same form. (Or maybe it's about half and half.)
In Spanish it's esto vs. este, and in Japanese it's "kore" vs "kono".
This is bla bla bla, versus look at this thingy I have here