1① cp | ②male female | | ③ A B (表～) 2① cp | ②male male | | ③ A B (堂～) 3① cp | ②female female | | ③ A B (姨～) explanation: cp–couple ①–first generation ②–second generation ③–third generation In fact,there are three types of relationships,namely 表,堂,姨.The relationship between A and B depends on the relationship between their parents. 1.If A's father and B's mother are from the same couple,A and B are 表～. 2.If A's father and B's father are from the same couple,A and B are 堂～. 3.If A's mother and B's mother are from the same couple,A and B are 姨～. In ancient China, superiority and inferiority were orderly, so there was a more strict title. People can identify these relationships easily according to these prefixes. Nowdays we don't care much about these as while as it's still a puzzle for some Chinese.So these words can be seen much more less.

I'm not sure. Haha. Actually I like the simpler way the English speakers express them.

your father side is 堂，堂哥 elder brother cousin，堂姐 elder sister cousin，堂弟younger brother cousin，堂妹 younger sister cousin your mother side is 表, 表哥 elder brother cousin，表姐 elder sister cousin，表弟younger brother cousin，表妹 younger sister cousin

the daughters or sons of your mothers brothers or sisters(believed to be less close) the daughters or sons of your fathers brothers or sisters. (believed to be closer to you) Then 堂 and 表 implies subtle difference in closeness.