"The watch is in the purse."
Translation:Chiếc đồng hồ ở trong cái ví.
That is correct, but Vietnamese people tend to drop "đang" UNLESS they're really trying to emphasize an ongoing action/condition.
For example: "Cái đồng hồ tui ĐANG ở trong cái giỏ mà nó lấy mất hồi nào không hay!!!" (My watch was right inside my bag but they somehow stole it without my knowledge). "Tôi ĐANG làm việc đổ mồ hôi mà không thấy sao??" (Can't you see I'm working very hard here? Implying "why are you bothering me while I'm working so hard that I'm sweating.")