can i tap {llanowar elves} for its normal mana and have it count as tapping for {heritage druid}'s ability? so in total i would have 4 mana if so what rules?
Unfortunately, tapping them is part of the cost to recieve the ability. So you cannot tap something for 2 abilities.
No. The requirement before the colon is the cost to use the ability. If you tap Llanowar for mana, he's already tapped for the Heritage Druid.
Nope. That wouldn't work. Heritage druid's ability is part of the cost for its ability. Tapping your elves in another way will not let you pay the cost. You can either use llanowar elves as part of the cost for adding {G}{G}{G} to your mana pool, OR you can pay the cost of tapping llanowar elves to add {G} to your mana pool.
Well, looks like you got 3 answers :P
alright thats what i figured but my friend didnt think so thanks for clarrifying that!:)