Final answer:
The best fit for the sentence given the author's disapproval of arguing would be 'stubborn' due to its negative connotation, contrasting with 'determined', which has a positive connotation.
Step-by-step explanation:
In the sentence "I hate arguing with Sam; he is just so (stubborn, determined)", the word with the connotation that best fits the sentence is stubborn. This is suggested by the author's tone of disapproval towards arguing with Sam, implying a negative attribute.
The word 'stubborn' has a negative connotation and implies being unreasonably inflexible or unwilling to change, which aligns with the sentiment of 'hate' expressed towards arguing. On the other hand, 'determined' carries a positive connotation, suggesting perseverance and a strong will to achieve goals, which does not align with the negative tone of the sentence.
Connotations are important in conveying the correct sentiment and tone in writing. For instance, describing someone's actions with positively connoted words such as 'determined' can imply admiration, while using negatively connoted words like 'stubborn' might indicate irritation or disapproval.