Sentence examples for activities were from inspiring English sources

"activities were" is a grammatically correct phrase and can be used in written English.
It is often used to indicate that multiple activities took place in the past. Here are some examples: 1. "Last summer, our daily activities were filled with hiking, swimming, and camping." 2. "The children's activities were scheduled from 9:00 am to 3:00 pm." 3. "The company's team-building activities were a huge success." 4. "During the lockdown, our main activities were working from home and binge-watching TV shows." 5. "The activities were carefully planned and executed for maximum impact."