The Weekly Shtikle - Sukkos
As part of the requisite mitzvos pertaining to Sukkos, we are told (Vayikra 23:42) "You shall dwell in sukkos for a seven day period." It is interesting to note that the word sukkos is in plural. The first inclination would be that this because the nation as a whole will dwell in many sukkos. However, the adjacent mitzvah of the four species refers to the esrog and the lulav in singular form, despite the fact that the nation as a whole will be taking many of those. Why, then is the wording for the mitzvah of sukkah different?
There is a big difference between the mitzvah of sukkah and that of lulav and esrog. The mitzvah to take a lulav and esrog is very personal and private in nature. This is epitomized by the fact that one must own their own four species and cannot fulfill the mitzvah with someone else's.
The mitzvah of sukkah, by contrast, is one that naturally includes others. Everyone makes the sukkah their temporary dwelling, the place where they eat all of their meals. Some are unable to make their own. Families and individuals, whether they have their own sukkah or not, are almost certain to share this mitzvah with others, either by eating in their sukkah or inviting them eat in their own. You will be hard-pressed to find an individual who goes the entire sukkos only eating in one sukkah. Therefore, the mitzvah of sukkah is given in the plural because it is the intention that one should eat in many sukkos whereas the mitzvah of lulav and esrog can only be fulfilled with one set of the four species.