Affirming the Consequent, Denying the Antecedent.
Even if both premises are true, the syllogism may still be invalid.
Antecedent 
Consequent 
Affirming the Antecedent (correct) 

If A If I work at Victoria's Secret 
Then B I must be sixteen or older. 
A I work at Victoria's Secret 
Then B Therefore I am over sixteen. 


Denying the Consequent (correct) 

If A If I work at Victoria's Secret 
Then B I must be sixteen or older. 
Not B I am not yet sixteen 
Then Not A I do not work at Victoria's Secret 


Affirming the Consequent (incorrect) 

If A If I work at Victoria's Secret 
Then B I must be sixteen or older. 
B I am over sixteen 
Then A I work at Victoria's Secret 


Denying the Antecedent 

If A If I work at Victoria's Secret 
Then B I must be sixteen or older. 
Not A I do not work at Victoria's Secret 
Then Not B Therefore I am not yet sixteen 
If I am a student at Wake Forest, then I am in college.
If I am eating shrimp, I am eating seafood.
If I am driving a Lexus, I am driving an automotive vehicle.
If I am at the Louvre, I am in Paris.
If McCain wins in South Carolina, he will win the nomination.
If I work at Victoria's Secret, then I am sixteen or older.
If I have eaten spaghetti, I must like Italian.
If my birthday is July 16, my sign is Cancer.
If play in the ACC, then I am a division I athlete.