Identify the error in the following sentence: 'The dog wagged it's tail excitedly.'

The incorrect use of 'it's' instead of 'its'.

Correct the following sentence: 'My friends and me went to the movies.'

My friends and I went to the movies.

Having finished the test, she left the room.

The pronoun 'their' should be 'his or her' to agree with the singular pronoun 'everyone'.

The students, along with the teacher, is going on a field trip.

I can identify and correct grammatical errors in sentences similar to those on the ACT.

1
Commas are used to separate items in a list, to indicate a small pause or shift in a sentence, and to separate nonessential words, phrases, or clauses.
2
FANBOYS (For, And, Nor, But, Or, Yet, So) conjunctions connect two independent clauses, and a comma should be placed before the conjunction.
3
Apostrophes are used to show possession or to indicate a contraction, but should never be used to pluralize a word.