It should be : We will go to Japan, stay there 4 days then go back to us. Or : We will go to Japan and will stay there 4 days then go back to us.
Ra'ed Sorry, but your sentence is not acceptable. You have omitted important punctuation marks, and US must be capitalised. PaulM
Sorry, I didn't recognize that It should be : We will go to Japan, stay there 4 days then go back to US. Or : We will go to Japan and will stay there 4 days then go back to US.
"We will go to Japan, stay there for four days, and then return to the US / United States". PaulM
Thank you 👍