PART 2 of the Third and Final: http://www.italki.com/question/202815

Is this an appropriate way to answer this question?
এইভাবে প্রশ্ন দেওয়া যাই
>>Correct=>এইভাবে কি প্রশ্নের উত্তর দেওয়া উপযুক্ত / দেওয়া যায়? (*Please DO NOT use দেওয়া যায় if you are talking in a formal way and to someone you show respect to, esp towards teachers during an exam, or during a job interview. However, since you are living in Canada, I believe that you wouldn't have to be worried about this fact! ;D)

Did you waste the boss’s time on your blabbering?
তোমার পেকপাক করা মালিকের সময় শেষ হইল? (The word is প্যাঁক প্যাঁক and it can be used to seriously insult or blame badly about someone, so special care is needed during using these kinds of Bengali adverbs!)
>>Correct (and more natural)=>তুমি কি অতিরিক্ত কথা বলে মালিকের/Boss-এর সময় নষ্ট করেছ?
*অতিরিক্ত (extra)কথা বলা= means talking too much.
**'Boss-এর' sounds fine even though 'boss' is an English word.
***নষ্ট = (to) waste [<-if you are using it as a verb]

Didn’t you supervise the exam yesterday?
কালকে আপনি আপনার পরিক্ষা দেখশোনা করি নি
>>Correct=> গতকাল কি আপনি পরিক্ষার তত্ত্বাবধান করেননি ?
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THE END!!!

Your Bengali is very very good! How did you and what made you interested in learning Bengali? Please tell me if you don't have any problem letting others know about it!
Do your best. Until next time (^_^)

PART 1 of the Third and Final: http://www.italki.com/question/202815

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What time is it appropriate to talk to you?
কোন সময় অপনার সাথে কথা বলা উছিত উপযুক্ত?

I came here to talk about the transportation system to summer school.

<em>Please note that in Bangladesh we don't have anything as "Summer Schools". Cool, right? Who would love having going to schools even during vacations? At least, not me!!! However, that is why I think the "গ্রীষ্ম স্কুল" part wouldn't make any sense in Bengali or if you are talking to any Bengali person (unless he/she is familiar about Western culture or at least about "Summer Schools")</em>

আমি (এখানে) গ্রীষ্ম স্কুল(Summer school) পরিবহন সিস্টেমের সম্পর্কে ব্যবস্থা সম্বন্ধে কথা বলতে এসেছি 

You are on your own.
তোমাকে সব কিছু শেষ করতে হবে

>>Correct=> তোমাকে (সব কিছু) নিজে করতে হবে   <em>(সব কিছু=everything)</em>

তোমাকে একাই সব করতে হবে 

*Notice that a direct translation of the English sentence (which is a kind of idiom in English) would be pretty much meaningless in Bengali. My (also your) sentence/translation is more natural and a direct translation to English is "You have to do everything yourself".

PART 2 of the Second: http://www.italki.com/question/202816

I am sorry to hear about your wife.
আমি আপনার স্ত্রিএর সমপর্ক দুঃখিত (you didn't translate 'hear' in your translation)
>>Correct=>আমি আপনার স্ত্রীর সম্পর্কে/সম্বন্ধে শুনে দুঃখিত ।

It is obvious that he committed the crime.
>>এটা স্পষ্ট যে সে/*তিনিই এই অপরাধটি করেছে/করেছেন
*Adding the ~ই after তিনি makes it sound like "He is the ONE who commited the crime" and it supports the phrase "It is obvious that~"
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No problem! Here is the second one. Please ask me if there are any explanations you couldn't understand...^_^

PART 1 of the Second: http://www.italki.com/question/202816

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You have our deepest sympathy.
আপনাদের কাছে সহানুভূতি
>>Correct=>আপনার কাছে আমাদের গভীর সহানুভূতি রইল
*(Deep=গভীর),(রইল=a formal word meaning "stays". To direct-translate the Bengali sentence it would be-> "Our deepest sympathy stays with you")

I decided to teach those kids a lesson.
আমি ঐ বাছাদের জব্দ করতে চাই (জব্দ is a bit serious and/rude sometimes!!!)
>>Correct=>আমি ঐ বাচ্চাদের/*ছেলেদের শিক্ষা দিব/দেওয়ার সিদ্ধান্ত নিয়েছি ।
*It would be better to use ছেলেদের if the 'kids' you are referring to are boys. Also, by mentioning about "lesson" you are meaning that you will make them pay for something (not literally!), right? শিক্ষা দিব means 'to teach a lesson'. This could also refer to lessons being taught by teachers. However, the tone that you will be using relative to the situation would confirm what you want to mean. I hope this explanation wasn't very difficult. If it is, please ask me again ^_^

I am different from other people.
অমি আরেকজন থেকে আলাদা
আমি অন্যদের থেকে আলাদা (আরেকজন=>another specific person, অন্যদের=other people; does not refer to any speific person)

Thank you RJ!