How much do you know? 3

If someone says, "I had a busy day today. I'm going to hit the sack," what are they planning to do?

If a friend says, "I reckon it's going to rain today," what's the meaning of "reckon"?

"He’s been crook all weekend, just lying in bed." Whta's the meaning of "crook"?

When someone says, "Let’s have a barbie," what are they suggesting?

"What time do you knock off work?" What's the meaning of "knock off"?

When someone says, "The supermarket was chockers, I couldn't move!" What do they mean