Starting with some classic examples:

1. Without comma: "Let's eat Grandma!"
    
2. With comma: "Let's eat, Grandma!"

(The first sentence suggests cannibalism, while the second is a dinner invitation.)

1. Without comma: "I love cooking my family and my dogs."
    
2. With comma: "I love cooking, my family, and my dogs."

(The first implies a rather disturbing culinary preference, while the second lists things the speaker loves.)

1. Without comma: "We're going to eat kids!"
    
2. With comma: "We are going to eat, kids!"

(The first one again suggests cannibalism, the second is a call for dinner time.)

1. Without comma: "A woman without her man is nothing."
    
2. With commas: "A woman, without her, man is nothing."

(The meaning changes dramatically from a sexist statement to one empowering women.)

1. Without comma: "I'm sorry I love you."
    
2. With comma: "I'm sorry, I love you."

(The first expresses regret for loving someone, while the second is an apology followed by a declaration of love.)

1. Without comma: "Don't stop dancing girls!"
    
2. With comma: "Don't stop, dancing girls!"

(The first could be interpreted as an order not to prevent girls from dancing, while the second encourages dancing girls to continue.)

1. Without comma: "I'd like to thank my parents Ayn Rand and God."
    
2. With comma: "I'd like to thank my parents, Ayn Rand, and God."

(The first implies Ayn Rand and God are the speaker's parents, while the second lists three separate entities being thanked.)

These examples highlight the importance of proper comma usage in written communication to avoid misunderstandings and convey the intended meaning clearly.

More complex sentences

Here are some more complex sentences that demonstrate how comma placement can significantly alter meaning:

1. Without commas: "The professor said the student is crazy."
    
2. With commas: "The professor, said the student, is crazy."
    

(The first sentence suggests the student is crazy, while the second implies the professor is crazy according to the student.)

1. Without comma: "I have a dream that one day this nation will rise up and live out the true meaning of its creed we hold these truths to be self-evident that all men are created equal."
    
2. With commas: "I have a dream that one day this nation will rise up and live out the true meaning of its creed: we hold these truths to be self-evident, that all men are created equal."

(The commas and colon in the second version make Martin Luther King Jr.'s famous quote much more readable and impactful.)

1. Without commas: "The man who hunts ducks out on weekends."
    
2. With commas: "The man, who hunts, ducks out on weekends."
    

(The first sentence is about a man who hunts ducks, while the second is about a man who avoids his commitments on weekends.)

1. Without commas: "I'm opposed to taxes which discourage economic growth."
    
2. With commas: "I'm opposed to taxes, which discourage economic growth."
    

(The first sentence implies opposition only to specific taxes that discourage growth, while the second suggests opposition to all taxes, stating that they discourage growth.)

1. Without comma: "The protester who were unarmed were arrested."
    
2. With comma: "The protester, who were unarmed, were arrested."
    

(The first specifies that only the unarmed protesters were arrested, implying others were not, whereas the second implies all protesters were unarmed and arrested.)

1. Without commas: "The defendant said the witness is a liar."
    
2. With commas: "The defendant, said the witness, is a liar."
    

(The first accuses the witness of lying, while the second accuses the defendant of lying.)

1. Without commas: "I detest liars like you people who are always honest make me sick."
    
2. With commas: "I detest liars. Like you, people who are always honest make me sick."
    

(The first sentence is confusing and contradictory, while the second clarifies the speaker's aversion to honesty.)

These examples showcase how crucial proper punctuation is in more complex sentences to ensure clarity and prevent misinterpretation.