Can I Give Home Remedies For My Son ?

The youngest son is having serious cough now. Not only during the night but most of the time he also cough in the day. I give him cough syrup but the effect of the syrup probably will take longer than expected. Can I give home remedies to my son to stop this cough? What kind of home remedy that I can give to my five years old son? I am searching and browsing now but so far, I did not see something that can help me to solve this matter. Any idea, my friends?