I have sometimes seen 很多 after the noun and sometimes before and I don't understand what the reason is for it being in different places.
For instance, here it follows the noun, "活动":
中国的居民社区的休闲活动很多 There are many leisure activities in the residential communities of China.
However, in another sentence I've seen, it comes before the noun, "社区":
在中国，很多社区都有 老年大学 ，经常组织书法课堂活动。 In China, many communities have old people’s universities which often organize calligraphy classes.
Similarly, before the noun phrase, "退休的老年":
很多退休的老年居民都参加这个活动。Many retired elderly residents participate in this activity.
What is the reason for these various locations of 很多?