Is it common for schizophrenics to switch back and forth between "personalities" instantly?

I know there’s no connection between schizophrenia and dissociative identity disorder, but its as if my wife really does have two personalities and she can switch back and forth between them in a second. Usually each personality might last for hours but I’ve seen her switch to one for a single sentence and then back again and then the first one wondered who said that single sentence.
I suppose this is just a manifestation of the illness that makes it appear as two personalities, but Is this instant switching common?

My son does the same but has complete conversations with his other personalities. He even argues with them and it can be very scary to hear and watch. He has about 5 -6 different personalities that I call his alto egos and these personalities were his voices that are now real people to him.So instead of just hearing his voices he now sees and communicates with both the bad and good ones. They travel in the car with us with him opening his door and waits for them to get in.If I try to leave he yells that one of them isn’t in the car yet so I must sit and wait for all of them to enter. Needless to say, I don’t take him with me as much as before.
One personality may be stronger then the others and dominate for awhile so maybe that is what is happening with your wife.My son’s doctor is very aware of this and has said it is not personality disorder but is another symptom of this illness not experienced by all.

I have seen my son switch as you are describing. My husband called my son’s second persona “night guy”. When cycling through lighter phases my son was awake in the daytime and slept at night. When he cycled toward heavier psychosis, the first indication that he was about to get worse was the change in his sleep schedule. “Night guy” stayed up all night and sometimes never slept at all.

My wife has a nice soft affectional adorable personality and a hard angry non-affectionate sarcastic one. The tone of voice, facial expressions, even the smiles are different. The soft personality doesn’t remember being the hard one, the hard one seems to (I once asked her about something and she replied - “I don’t know, maybe it was one of my selves”).
The soft one agrees with me she should see a doctor, though she doesn’t think she’s ill and doesn’t see why she needs to go but will do so because I ask her to; the hard one is adamant against it and gets angry if one is mentioned. The soft one is thankfully there most of the time, but unfortunately when I’ve had an appointment scheduled with the doctor (which I did with the agreement of the soft personality) then the hard personality emerges and refuses to go.
If its going to always be this way I don’t see how can I ever get her to see a doctor, never mind take any meds.

You can see why in history scz was considered a split personality situation. Read the threads here, see how others got their family members taking meds and try to figure out which method would work for your wife.

Attending NAMI’s Family to Family class is a good way to start educating yourself. Reading Dr Amador’s “I’m Not Sick, I Don’t Need Help” and watching his videos online at youtube can be helpful.

When my son first started to show what I now know were probably symptoms, at about age 5, he used to draw a person named “Fireball” and make up stories about him. Fireball was a teenager, with green-dyed hair and a scarred face, who would do violent things and generally make trouble. I never imagined that Fireball would come to live with us.
My son is now 14, and had his first real psychotic episode in February. He was delusional, physically violent, sarcastic, emotionally cold - not at all what he’s like when he is feeling well. I understand why people once thought that people with psychosis were possessed by devils. Also why they thought it was a “split personality” - even his facial expressions are different than normal during an episode. It was terrifying for all of us, including my son.
Things are a lot better now that my son is on medication and receiving therapy. He really doesn’t want to have more episodes, so he is fortunately very cooperative about taking medication and going to sessions. I only wish there was truly a cure.

My daughter also has several identities that she switches between. She speaks as if she is the person she’s taken the identity of and even changes her voice. She is talking continuously as all these different identities, often talking to each other. One is her ex boyfriend, several are her dead pets, and one is the mother of all creation. It can be quite distressing to watch and it’s very difficult to get her attention, in effect to switch to her real identity. We thought perhaps this was an additional illness to schizophrenia but now that I’m reading other people who have the same presentation, I’m inclined to think it’s just another symptom of schizophrenia.