If it has feathers, it is a fledgling and could be learning to fly. Therefore, it should remain on the ground - only remove it if it is in danger from a predator, or the parents do not return within one hour. If the bird has no feathers, it is a nestling, so look around to see if you can spot the nest. Gently pick him up and place him back in the nest. House Sparrows were originally recorded in Eurasia, North Africa, and the Middle East but now live all around the world. Because there are so many sparrows globally, they are not a protected species. This means there are no laws prohibiting them being kept as pets. It is not advisable for pregnant women or people with compromised immune systems to handle baby birds. They may carry diseases, such as salmonella, which can infect humans. Always observe strict hygiene when handling the bird. Thoroughly wash your hands before and after care. Dispose of waste in a sealed bag. If the bird has too much human contact, it may start to think you are its parent and will lose its fear of you. This makes it difficult to release the bird back into the wild. If your intention is to rear the bird to a stage when it is strong enough to be released, then avoid picking the bird up and handling it, especially during feeding. You want to retain the bird's natural fear of humans.  Try to avoid the baby bird becoming imprinted on you. This means the bird assumes he is human rather than a bird and can lead to difficulties when releasing him back into the wild.  Do your best to avoid speaking to the bird. The goal should be to feed and care for the bird as if you are an "invisible force." Nestlings and fledglings are fed on an all insect diet by their parents, and do not drink water. If you try to drip feed the bird water, you stand a good chance of it inhaling water and drowning.

TL;DR in Vietnamese:
Xác định chắc chắn là chú chim bị bỏ rơi. Bảo vệ sức khỏe khi tiếp xúc với động vật hoang dã. Tránh để lại ấn tượng sâu sắc với chim. Tránh cho chim uống nước.