Can a Protestant generally go to a Catholic Church on Sunday?

Yes, generally speaking, a Protestant can attend a Catholic Church for worship on Sunday or any other day. While there are doctrinal differences between Protestantism and Catholicism, many Protestants are open to visiting Catholic churches for various reasons, such as curiosity, attending special events, or joining friends or family members for worship.

However, it's important to be respectful of the practices and traditions of the Catholic Church when attending Mass. Catholics have specific rituals and customs during their worship services, including the Eucharist (Communion), which has particular significance within Catholic theology. While non-Catholics are welcome to attend Mass, they should refrain from participating in certain aspects of the service, such as receiving the Eucharist, unless they have been formally received into the Catholic Church through the sacrament of Confirmation.

Additionally, it's courteous to dress modestly and respectfully when attending any religious service, regardless of denomination.

Ultimately, whether a Protestant attends a Catholic Church is a personal decision, and many find value in experiencing different expressions of Christian worship and community.