Activities

Hobinya = hobbies
Apa hobinya? = What hobbies?

Playing computer = main komputer
Playing the guitar = main gitar
Playing soccer = main sepak bola
Playing basketball = main bola basket
Playing tennis = main tenis
Playing the piano = main piano
Flying a kite = main layang-layang
Playing a congklak = main congklak

Reading the newspaper = membaca surat kabar (membaca = read, surat kabar = newspaper)
Listening to music = medengarkan musik (medengarkan = listen, musik = music)
Drinking tea = minum teh (minum = drink, teh = tea)
Studying = belajar
Cooking = memasak
Washing the car = mencuci mobil
Sewing = menjahit

So therefore...

My hobbies are playing the guitar and piano = Hobi saya main gitar dan piano (dan = and)
His/her hobbies are cooking and playing the computer = Hobinya memasak dan main komputer

If sedang is an action word (-ing) in progress in a written form, and lagi indicates an action word (-ing) in progress in a spoken form....:

I am [currently] sewing = Saya sedang menjahit is the written form, and lagi menjahit is the spoken form

What are you doing, Natasha? - lagi apa, Natasha?