I need some English help please. What is simple subject and simple predicate in the sentences below?

see below

1. simple subject: workmen simple predicate: repaired

2. simple subject: class simple predicate: laughed

3. simple subject: day simple predicate: ended

4. simple subject: hours simple predicate: passed

Note: Simple subject is the noun/pronoun that the sentence is talking about. It does not include any of the adjectives modifying the subject.

Simple predicate is the specific action/verb that the subject did. Simple predicate may be a verb phrase (main verb with auxiliary verb). It does not include adverbs or other modifiers for the verb.