My desire to become an excellent accountant makes me enthusiastic, motivated, focused, and an excellent fit for this job.
Is it right to put a comma before "and" ?
Answer to your question
Comma or no comma is accepted.
According to https://www.grammarly.com/blog/what-is-the-oxford-comma-and-why-do-people-care-so-much-about-it/
Use of the Oxford comma is stylistic, meaning that some style guides demand its use while others don’t.
But, personally I think it's a good habit to use it, one reason being because it prevents what above article refers to as "strange misunderstandings".
By the way
The structure of your sentence should be grammatically reconsidered. Although joining different parts of speech by a conjunction like "and" is done sometimes informal speech, from a "strictly speaking" perspective, the list should include only one part of speech:
From https://en.wikipedia.org/wiki/Conjunction_(grammar)#Coordinating_conjunctions
Coordinating conjunctions, also called coordinators, are conjunctions that join, or coordinate, two or more items (such as words, main clauses, or sentences) of equal syntactic importance.
I interpret "syntactic importance" to include part of speech. If it really doesn't, in this case it still wouldn't hurt to err on the side of strict interpretation.
On that note:
In your sentence, the following function as adjectives:
- enthusiastic
- motivated
- focused
However, the following functions as a noun:
- fit
So, one way to start restructuring is the following:
My desire to become an excellent accountant makes me enthusiastic, motivated, and focused, and it makes me an excellent fit for the job.
Changing the meaning a little bit for conciseness, we can use the following:
I am an excellent fit for the job because my desire to become an excellent accountant makes me enthusiastic, motivated, and focused.
Tying everything back to your original question, note that I used the Oxford comma :)
