I know both mean "to study" and I also know that while 学 (xué) is transitive, 学习 (xué xí) can be both intransitive and transitive, for example: 我学中文。 (I study «what?» Chinese) = transitive; 我在大学学习。 ...
Both 浪费 and 糟蹋 mean "to waste." (I'm not really concerned with the other uses of 糟蹋 right now.) I've seen the collocations 糟蹋粮食 and 糟蹋人才, and 浪费 is very common in phrases like 浪费时间 and 浪费水. Are ...