I learned that a sentence has different parts. These are subject, verb, object, manner, place, and time.
For example:
Maria and her sister attend classes online.
Subject: Maria and her sister
Verb: attend
Object: classes
Place: online
They learn English quickly.
Subject: They
Verb: learn
Object: English
Manner: quickly
Maria submits her homework at night.
Subject: Maria
Verb: submits
Object: her homework
Time: at night
They meet their classmates in the park.
Subject: They
Verb: meet
Object: their classmates
Place: in the park