He seems not to know how/ what to play with things. He has a reasonable range of toys, has an elder brother so lots of stuff around. But he will virtually never just pick something up and play with it. He has a role model of sorts, elder DS is really into playing with lego/construction stuff, as well as his soft toys, bless him! And over the years I have tried sitting with DS2 to 'help' him play, sort of get him started, but he seems to clam up even more. If asked what he enjoys doing, he replies 'nothing', or 'telly', or 'eating chocolate cake'. If I try to force anything he just says 'thats boring.' So when telly is off(which is plenty before anyone asks!!) he either just sort of hangs around like a mopey teenager or plays with DS1 if he is free. Everything else is boring 
What I see him enjoying - playing rough and tumble with me/dad/brother; outdoors stuff eg cycling/trampolining; playing with older brother with soft toys where he follows DS1's game rules! Thats it. How can I help expand his range of interests a bit..?