When is たら or 時 being preferred more than the other?


たら and 時 can be used to say "when" expressions. I have learned these
grammatical expressions already. In the book みんなの日本語, there is a question that
goes...

> 昼ご飯を a.食べた時 b.食べたら、すぐ出かけます。

When seeing this, instantly I would pick 'b'. However I can't explain to
myself why it had to be 'b' when 'a' doesn't sound grammatically wrong. Is it
perhaps the すぐ that made it that way?




Because 時 means "the time when" but not "then". The word "when" seems to mean
the both.

昼ご飯を食べたら、すぐ出かけます would be translated as "After eating breakfast, (then) I will
go out soon."

Does 昼ご飯を食べた時、すぐ出かけます(The time when I ate breakfast, I will go out soon.) make
sense?




Because 時 means "the time when" but not "then". The word "when" seems to mean
the both.

昼ご飯を食べたら、すぐ出かけます would be translated as "After eating breakfast, (then) I will
go out soon."

Does 昼ご飯を食べた時、すぐ出かけます(The time when I ate breakfast, I will go out soon.) make
sense?

