1) "It's difficult for me." 2) "After the hiring process, how long will it take before I start working?" (I understand your sentence, but we usually describe this question in a lengthier way. My example is one way to ask this.) 3) "When I finish with my work (<< more natural way to word this), can I stay late to learn more from my coworkers or help them if they need anything?" (Once again, a possible way to word this but there are many other ways you could explain this same idea.) 4) "no, I didn't / no, I didn't do it" (Both are correct. The first sounds more natural. The second would probably be more appropriate for situations where you are adding emphasis.) 5) "I have wanted to be here for a long time." (This sounds natural. If you say "since," you would do better to choose a specific moment in time--such as "since I was a child." 6) "walking" 7) "You have to sweep, clean, study and learn." (If you say "both," this word refers to the presence of two items, tasks, etc. However, you are referring to more than two items here.)

1) It's difficult for me 2) If you hire me, how long till I start working 3) If I finish my work early, can I stay to learn more from my coworkers or maybe help? or more simply: Can I work longer hours to learn more form my coworkers? 4) Did you do it? - no, I didn't / no, I didn't do it <- both good 5) I have always wanted to be here. or I have wanted to be here for a long time. (Always is always) 6) That's better than walk/walking with those shoes No clue what you mean here - rephrase it, maybe? 7) ? You have to do the sweeping, the cleaning, the studying and the learning. You have to sweep, clean, study and learn. You have to do all, the sweeping, the cleaning, the studying and the learning.