问题 I thought Sam was sick.是虚拟语气吗

I thought Sam was sick.这句话是虚拟语气吗？如果是虚拟语气，那是主句动词 thought 虚拟还是在从句的 was 虚拟。如果不是虚拟语气，那又该怎样解读？谢谢专家老师！

话题 it was that

话题 was plainly done

话题 was distressed about

话题 it was until

话题 as was expected

话题 was speaking of

话题 than was expected

话题 If it was

话题 than was thought

话题 was/is 时态问题

话题 as it was

问题 如何判断现在分词短语是作原因状语还是时间状语

Venmo is not yet profitable, having been deliberately slow in starting to introduce fees and other moneymaking features.这句话中having been slow.....features是作原因状语还是时间状语？怎么翻译？

问题 It was yesterday还是It is yesterday（另外no后面为何没有逗号）

It was yesterday, no actually it was Monday morning. 是昨天，不，应该是星期一早上。这个句子中的两个 was 用得对吗？感觉应该是用 is 才对啊！另外，这个 no 后面为什么没有逗号呢？

问题 as if后面的虚拟语气中用was与were的区别

学习中遇到的例句是这样的。He writes as if he is / were / was left handed.解释中说道：is 表示他应该真的是左撇子，were 表示他不是，只是冒充左撇子。到这里我都可以理解。但是又说，was 则表示不一定——可能是，也可能不是。was 怎...