Remember that you need to place a comma after introductory elements in your sentences.
Introductory elements come before the main clause of a sentence and prepare the reader for the "meat" of the sentence.
Introductory elements can include the following:
Prepositional phrases: In the morning, I went to school.
Adverbial phrases and clauses: When I wake up, I will go to school.
Dependent clauses: Because I drank sour milk, now I don’t feel well.
There are other introductory elements as well, but the thing they all have in common is that they come before the main subject and verb of a sentence. They tell why, when, or where.
Don’t forget these commas!