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