Prepositions – ‘In Addition To’ Vs. ‘In Addition Of’

prepositions

I stumbled upon the sentence:

This book is dedicated to my mother, who has taken care of her family throughout her life without the slightest negligence, in addition to being sincere towards her duties as a school teacher, […]"

I was wondering about the "in addition to". Grammatically, the preposition "in addition to" is correct, but for me, as a non native english speaker, it reads strange.
Probably because of the following "being".

Wouldn't one rather use a "besides" or "in addition of" instead, or is an "in addition of" generally wrong?

Best Answer

"In addition of" is totally wrong. The preposition (when present) is always "to".

However, there are at least two situations where "of" appears next and it is not a mistake.

  1. When the phrase "in addition" has completed, and the sentence continues with yet another phrase.

In addition, of all the weather satellites in orbit, only DMSP can "see" at night.

  1. When referring to mathematical addition.

Instruction and practice in addition of fractions