Use of commas When to use commas? You would use a comma when you are trying to separate concepts with a subject in a sentence. For example, "I went to the store today, and I bought some bananas". Is this the correct use of comma? Yes, because the subject is "I". Another example: "I went to the store today and bought some bananas". Is this the correct use of non comma? Yes because there is no mention of a subject for the second part of the sentence.

Use of prepositions at the end of sentences Is it correct to use prepositions (on, of, from) at the end of sentences? Ideally, it would be best not to do so (placing them at end of sentences makes the dialogue informal). For example: "Which magazine is your writing published in? (Informal) "In which magazine is your writing published? (Formal) Notebook