Using or omitting articles with school, university, prison, hospital, church, bed and similar nouns.
Do not use an article before school when referring to education. Use the when referring to the building or a specific school.
"Go to school" means to attend as a student. "Go to the school" refers to visiting the building or a particular school.
Do not use an article before university or college when referring to studying there. Use the when referring to the institution or its buildings.
British English commonly says "at university". American English usually says "in college". The is used when referring to a specific university or campus.
Do not use an article before hospital in British English when referring to medical treatment. Use the when referring to the building or a particular hospital.
Compare "She is in hospital." and "She is at the hospital visiting her friend." American English generally uses "the hospital" in both meanings.
Do not use an article before prison or jail when referring to imprisonment. Use the when referring to the building or visiting it.
Compare "He was sent to prison." and "His wife went to the prison to see him."
Do not use an article before church when referring to attending a religious service. Use the when referring to the building.
Compare "They go to church every Sunday." and "The tourists admired the church."
Do not use an article before bed when referring to sleeping or resting. Use the when referring to the piece of furniture.
Compare "Go to bed." and "Sit on the bed."
Do not use an article before home when referring to returning or being at one's home.
Compare "Go home." and "The house is the home of a famous writer."
Do not use an article before work when referring to employment or the workplace generally.
Compare "She is at work." and "The work was difficult."
Do not use an article in expressions such as "go to sea" when referring to a sailor's profession. Use the sea when referring to the body of water.
Compare "He went to sea at eighteen." and "We swam in the sea."
Do not use an article before court when referring to legal proceedings. Use the when referring to the courtroom or building.
Compare "She appeared in court." and "The reporters waited outside the court."
Whether an article is used depends on whether the institution is viewed by its function or as a physical place.
Many nouns such as school, hospital, prison, church and bed take the zero article when used for their primary purpose, but take the definite article when referring to the building, furniture or location.