Stephen - son
There are many reasons to learn how to divide Stephenson into syllables. Separating a word like Stephenson into syllables is mainly to make it easier to read and pronounce. The syllable is the smallest sound unit in a word, and the separation of the Stephenson into syllables allows speakers to better segment and emphasize each sound unit.
Knowing how to separate Stephenson into syllables can be especially useful for those learning to read and write, because it helps them understand and pronounce Stephenson more accurately. Furthermore, separating Stephenson into syllables can also be useful in teaching grammar and spelling, as it allows students to more easily understand and apply the rules of accentuation and syllable division.
In the case of the word Stephenson, we find that when separating into syllables the resulting number of syllables is 2. With this in mind, it's much easier to learn how to pronounce Stephenson, as we can focus on perfecting the syllabic pronunciation before trying to pronounce Stephenson in full or within a sentence. Likewise, this breakdown of Stephenson into syllables makes it easier for us to remember how to write it.