Re: I didn't know he was/is a marine
>>No offense but I just need some explanation to understand how to apply it in future.
I have a feeling future is more complicated, so first try to get a handle on past.
I looked around because I admit I didn't think my first response was very helpful. What I found was somewhat disheartening. There's all this stuff about what the speaker knows at the moment he says it and what is true now and what may be true but could possibly be false and …
I can get along in English pretty well in my sleep, but my head just spins when I try to understand all this. So let me try just repeating what I said before:
if the first verb is past tense, the second one should be past as well
This seems to apply to both military service and nervous kangaroos. You should be okay using this rule. I suggest slowly wading into the exciting world of exceptions to it.
A question comes to mind, and I hope this isn't off-topic: how do you say these things in your native language? You may take some encouragement from the fact that if this were a forum for learning to speak Chinese, my username would be imVERYconfused.
"When you are speaking for truth, and when you are speaking for justice, no one can defeat you." — Malala Yousafzai