The trip, which was paid for by the school, was very educational.
One museum that they planned to visit was closed.
I’ll try to expand on Jazy’s diagram analysis this way:
One museum was closed: Main clause
that they planned to visit: Subordinate clause, adjectival modifying the noun ‘museum’
One museum: Subject
was closed: Predicate
planned to visit: Predicate
Word Class Analysis:
One: Adjective, definite numeral
museum: Noun, common
was: Main verb of main clause, simple past, copular
closed: Adjective, participial
that: Pronoun, relative
They: Pronoun, personal, plural, accusative case
Planned: Main verb of sub-clause, simple past
to visit: Infinitive
Thanks for the full information. I am learning and like full explanations but I am confused regarding "They" being accusative case. Should this be nominative case?
Absolutely. You’re right. ‘They’ is in the nominative (subjective) case. My apology.