What are the best activities for a 4 year old child to learn at that age?

Kids at that age love all activities. Try to see what your kids interest are and work from there.

Art! If your child has interest in music, you can consider to send them to some music classes.

Refer to the following as reference: https://sg.theasianparent.com/4-years-1-month-old

Lots of lots of learning through play. Honestly, play is the best form of learning.

Music , dance, Swimming,skating , sports which ever he interested

Swimming art and music. My kid loves them all.

music, sensory play, swimming, reading

I put my kid in music and dance

Music class and swimming

swimming and piano.