Jan - nie
There are many reasons to learn how to divide Jannie into syllables. Separating a word like Jannie 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 Jannie into syllables allows speakers to better segment and emphasize each sound unit.
Knowing how to separate Jannie into syllables can be especially useful for those learning to read and write, because it helps them understand and pronounce Jannie more accurately. Furthermore, separating Jannie 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 Jannie, 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 Jannie, as we can focus on perfecting the syllabic pronunciation before trying to pronounce Jannie in full or within a sentence. Likewise, this breakdown of Jannie into syllables makes it easier for us to remember how to write it.