I looked up it on the internet and I found all of ‘the best stuff’.

Event-1 UNTIL Event-Event-2 Event-1 continues up to the time when Event-2 begins. EVENT’S STORAGE Event-1 BEFORE Event-2 Event-1 occurs earlier to the period when Event-2 begins.

So to make sure that I understand this fully, I made 2 right sentences and 2 wrong sentences. I try to act like I did a good job. And the more I do it, the better I be.

2 right sentences

Until you called me, I had been studying for about 3 hours and you laughed about me for my decision.

When you call me, I’d visited a store and purchased some ingredients, until you call me home.

2 sentences are wrong. Is that correct?

I bought good food at a store which I knew I just visited. How do you describe this?

How close were you to me before I called you back? I had been studying for 3 hours.

Why I can’t say to everyone that I respect their position on national security issues?