Legal Question in Civil Litigation in California

Yes. But you should consult an attorney in your area to discuss the claims asserted in the complaint and your potential courses of action (i.e. should you file a motion to quash, a demurrer, motion to strike, an answer, etc.). Just because you can do something doesn't necessarily mean you should. Further, even if it would be advisable for your to file a motion to quash, unless you want to spend some time at the law library figuring out how to do it, you should probably hire an attorney to help you.

The other Mr. Hoffman (no relation) offers some good advice. Bear in mind that the plaintiff can probably still serve you correctly. A motion to quash may just be an expensive way to buy some extra time, and may not be worthwhile. This is something to discuss with the attorney(s) you consult.

You should also look into whether the plaintiff has taken your default or even had a default judgment entered against you. Those actions would be void if you were not served correctly. He may be agree to set them aside if you were not properly served. But if he doesn't, you will need to bring a motion to set them aside along with a motion to quash service.

Good luck.