I've been studying all day, and I'm sick and tired of it.
我学了一天,现在感到厌倦。
I can't promise anything,but I'll do my best.
不敢保证,不过我尽力而为。
When we use a phrase like 'it serves him right', we are, in part, admitting that a certain set of circumstances has enabled justice to act of its own accord.