how many of a planeswalker abilities can you use per turn?

[robotman]

how many of a planeswalker abilities can you use per turn?

[Arix]

Only one per planeswalker.

[athos]

Here the official answer
:
306.5d Each planeswalker has a number of loyalty abilities, which are activated abilities with loyalty symbols in their costs. Loyalty abilities follow special rules: A player may activate a loyalty ability of a permanent he or she controls any time he or she has priority and the stack is empty during a main phase of his or her turn, but only if none of that permanent's loyalty abilities have been activated that turn.

[Kenji]

You revived a thread that was 3 and a half years old...to post an answer that was already given. Congratulations, I guess?

Seriously, though, thread necromancy is generally frowned upon. If a thread is older than a few weeks, it's probably not worth reviving for just about any reason -- so you can imagine how ridiculous it is to revive a thread that's multiple years old. =P

[Piplup]

does planeswalker tap?

[Arix]

Planeswalkers can be tapped (via cards like Flame Fusillade, or Gideon Jura becoming a creature and attacking, for example), but tapping a planeswalker doesn't really accomplish anything, as they function exactly the same regardless. Activating a planeswalker's ability does not cause it to tap (otherwise Gideon would be pretty useless).