This is the 255th most frequent Dutch word.
dezelfde
"The same."
The word 'hetzelfde' is used here in its neuter singular form because it refers to the neuter noun 'boek' (book).
Ik lees hetzelfde boek.
I am reading the same book.
The word 'dezelfde' is used here in its common plural form because 'interesses' (interests) is a common gender noun in the plural form.
We hebben dezelfde interesses.
We have the same interests.
The word 'dezelfde' is applied here in its common singular form to agree with 'jas' (coat), which is a common gender noun.