Simple sentences:
Example:
a) Some student like to study in the mornings.
b) Fauziah goes to the library and study everyday.


Compound Sentences:
Example:
a) I tried to speak English, and my friend tried to speak Spanish.
b) Adam played football, and Maria went to saloon.


Complex Sentences:
Example:
a) The students are studying because they have test tomorrow.
b) Juan and Maria went to the movies after they finished study.


Compound-Complex Sentences:
Example:
a) Although I like to go camping, I haven't had the time to go lately, and I haven't found anyone to go with.
b) We decided that the movie was too violent, but our children, who like to watch scary movies, thought that we were wrong.