1. Although Ernesto was running fever last night, he feels better today.
2. Ernesto was running fever last night, but he feels better today.
3. Ernesto was running fever last night; he feels better today.
Step-by-step explanation:
COMPOUND SENTENCE: When two independent clauses are combined together using a coordinating conjunction or a semicolon, the sentence becomes a COMPOUND SENTENCE.
Coordinating Conjunctions: For, And, Nor, But, Or, Yet, So
FOR EXAMPLE: Mary like to sing.
She likes to dance.
These are two simple sentences. We can combine the two sentences either using a coordinating conjunction or a semicolon making it a compound sentence .
Compound Sentence 1: Mary likes to sing AND she likes to dance. (combined the sentence using coordinating conjunction, AND)
Compound Sentence 2: Mary likes to sing; she likes to dance.
COMPLEX SENTENCE: When one independent clause is combined with one dependent clause using a subordinate conjunction, the sentence becomes a COMPLEX SENTENCE.
Subordinating conjunctions: Although, because, while etc.
FOR EXAMPLE: Although I was late for the exam, the examiner allowed me in.
“the examiner allowed me in” is an independent clause
“Although I was late for the exam” is dependent clause, i.e. the sentence is not complete, we need more information to complete it.
FOR EXAMPLE: ALTHOUGH I was late for the exam, the examiner allowed me in.