Even in your first job = Even while you are working at your first job.... How can you make more money at your job? = How can you make more money in your profession (doing the work you do)? Communicating on the job..... = work place dialogues = speaking with colleagues and coworkers.....

This question mainly has to do with tenses, past present and future. On the job=present/future tense, at your job=future tense, while in your job future tense. If your were talking about the past you would say while at my job... If your were talking about the future you could use on the job or at your job, for example when I'm at school... If your talking about present tense you could say, when I'm at school... When I'm at my job... This doesn't explain all of the different rules but I hope it helps a little!

Thank you 老鬼！介词短语真的很容易搞混，呵呵

English Prepositions 真的麻烦了！老鬼

1. in your job - in has a sense of duration or refers to the functions you fulfil in the occupation. In my job as a computer programmer I write share trading programs. 2. on the job - this is a set phrase, it only occurs as 'to be on the job' - it means you are actively doing something (that needs urgent attention). In fact it may have nothing to do with your real 'job' 3. at your job - refers to you performing your job, doing your job. Are you good at (doing) your job?