The word “cumulative” is one of those words which trip Caribbean natives. We often put the stress on the third syllable when it belongs on the first. Say “KYOO-myu-lah-tiv.”
Putting the stress on the right syllable can be challenging for Caribbean speakers when trying to speak standard American English. The syllable to be accented in four-syllable words is determined by various factors. They do follow patterns, but they’re not predictable. Some four-syllable words in Standard American English are accented on the first syllable, some on the second, and some on the third. Cumulative is an example of those that are accented on the first syllable.
Cumulative means increasing, growing, or building up little by little over time as new parts or amounts are added together.
In Standard American English, some four-syllable words are stressed on the second syllable, example: applicable. Some are stressed on the third syllable, example: comprehension. Some are stressed on the first syllable, example: cumulative. The syllable to be stressed is influenced by history, etymology, and several other factors.