I found it quite surprising to find both House Sparrows and Eurasian Tree Sparrows in the same place in Ho Chi Minh City!
I don't remember seeing them together in any city in the world.
While in Europe you won't find any Eurasian Tree Sparrows in urban areas, you will find Eurasian Tree Sparrows in almost every city in Asia.
House Sparrows are much rarer in Asia.
Male and female House Sparrows look different while male and female Eurasian Tree Sparrows look similar.
If you want to tell the two sparrows apart, remember that Eurasian Tree Sparrows have a brown cap and House Sparrows have a grey cap.

Ho Chi Minh City, Vietnam, 21 December 2023