Children are so smart , when my kids were this age I used to talk to them just in english , and if they wanted talk to me ,  they had to do it in english . Try it , in my opinion the best way is create an english enviroment , for example : daily tasks ( bath , have lunch , have dinner , watch TV , sleep , walking ) Begin speaking the name of the objects in english ( chair , table , shoes , toys ) Don't speak another language with your child for while , just english ...he will learn soon , and the best part : he will not forget his mother language , there are many searches about that on internet .

It works in all languages ! Good lucky !  God bless !