i was wandering in the future can bitcoin switch to proof of stake?
No. For any fork trying this an altcoin will evolve. Bitcoin will always be PoW.
No, it could switch to POS, POW is waste to much energy, the more important is POS is more secure than POW.
You need to convince everyone to switch, including hardware manufacturers (most are also users/merchants), pools and cloud providers. Won't happen anytime soon.
Also the concept of a stakeholder being able to sit back and collect new coins for doing nothing doesn't sit well with many people.