Comma before "though"

Question

I read somewhere that when we use subordinate conjuction in the middle of a sentence we don't, necessarily, use a comma. However I read some sentences today where a comma is used before though (in middle) in a complex sentence. Please guide.

He doesn’t like flying, though he enjoyed his trip to Italy last year.

Though he enjoyed his trip to Italy, he does not like flying.

According to my knowledge the first one has incorrect punctuation because "though" is in the middle of the sentence, but it is correct. I want to know how is it possible? Isn't there any hard and fast rule for using commas with subordinate conjunctions?

In conclusion, family encompasses a lot more people than just parents and children and moving abroad is not helpful in the terms of family development though it may be good for education and job prospects.

My teacher pointed a comma mistake before though in this sentence.

Answer 1

We generally surround a subordinate clause with paired punctuation when it is "unnecessary" (sometimes called "removable", "parenthetical", etc.). That would apply to your first sentence:

He doesn’t like flying, though he enjoyed his trip to Italy last year.¹

If we considered the clause important to the sentence's meaning, then we would omit paired punctuation:

You got that problem wrong because you wrote "12" though the correct answer is actually "11".

The same principle applies to your second sentence. Furthermore, another rule says that a modifier² at the beginning of a clause may generally be followed by a comma. Thus:

Though he enjoyed his trip to Italy, he does not like flying.

In your last sentence, the subordinate clause seems unnecessary, so I would include the punctuation:

Moving abroad is not helpful in terms of family development, though it may be good for education and job prospects.³

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¹The second comma of the pair is "absorbed" into the period at the end of the sentence.
²I'm using this word, but terminology will vary.
³I deleted the first part of this sentence, which is irrelevant for this issue, and deleted "the" for idiomaticness.

Answer 2

@Sudhir Sharma

(1) 'He doesn’t like flying, though he enjoyed his trip to Italy last year.'

and

(2) 'In conclusion, family encompasses a lot more people than just parents and children and moving abroad is not helpful in the terms of family development though it may be good for education and job prospects.'

In both examples, the dependent clause comes after its independent clause; hence, comma is not allowed.

(1) the comma before 'though' needs to be removed; (2) this is fine.