mtg can someone tap my creature if i tapped for an activation cost

[Alley]

can someone tap my creature if i tapped it for an activation cost?

[Arix]

They can try, but they won't accomplish much.

[Goober]

so if i tap a creature for its activated ability, can my opponent respond by using his creature's activated ability to tap my creature therefore canceling my creatures ability?

[Arix]

No. By the time your opponent gets a chance to respond, the cost has been paid and the ability is on the stack. No matter what happens to the creature afterwards, the ability will resolve as normal.

Besides which, the creature it already tapped. Tapping it again won't accomplish anything.

[Alley]

what about untapping it?

[Arix]

No. Again - the ability has already been played and is on the stack, whatever happens to the creature won't affect the ability.

[kip]

also if u exile the creature or kill it or take control of it, it still doesnt matter cuz the ability is already on the stack and will still resolve

[Goober]

what if my opponent tries to tap my creature, could i respond by tapping my creature for its ability?

[Josh]

yes