Pronunciation

I often have problems to pronounce correctly adverbs, nouns and adjectives.
The most frequent problem is where to put the accent (which vowel is to be stressed).

My dictionary has a tool which plays the pronounciation of the words but it's difficult for me to remember everything and it's difficult to reset bad pronunciations.

Let's make some examples:

acronym (I put the accent on o :Error and horror!)

exclusive

defective

defects

I systematically forget the correct pronunciation (accent) and wrong the pronunciation.