Write three sentences, each using a comma in a different way. Explain why the comma is needed in each sentence? Pls help

1. I went to the store, however, I didn't buy anything. The comma is needed here to separate the independent clause "I went to the store" from the dependent clause "however I didn't buy anything".

2. She was tired, so she decided to go to bed early. The comma is needed here to separate the two independent clauses "She was tired" and "so she decided to go to bed early".

3. The dog, a golden retriever, was running around the yard. The comma is needed here to separate the introductory phrase "The dog" from the rest of the sentence.

1. "I went to the store, picked up groceries, and returned home." - In this sentence, the comma is used to separate items in a list or series. It helps to clarify that "I went to the store," "picked up groceries," and "returned home" are three distinct actions.

2. "Sheila, my best friend, is coming over for dinner tonight." - Here, the commas are used to set off a nonessential phrase, which provides additional information about Sheila. It indicates that Sheila is already known to be the speaker's best friend, making it an optional element in the sentence.

3. "After finishing my homework, I decided to go for a walk." - In this sentence, the comma is used to separate two clauses in a compound sentence. It connects the dependent clause "After finishing my homework" with the independent clause "I decided to go for a walk," showing the relationship between the two actions.

1. I went to the store, bought some groceries, and returned home. (A comma is needed here to separate the three independent clauses to improve readability and indicate a pause between each action.)

2. My friend, who lives in New York, invited me to visit her this summer. (The commas are necessary to set off the non-essential clause "who lives in New York" to provide additional information about my friend.)
3. The concert starts at 8 p.m., so make sure to arrive early. (In this sentence, the comma is needed to separate the dependent clause "so make sure to arrive early" from the main clause to indicate a slight pause between the two ideas.)