2011-02-15, 04:46 AM
I believe you would need a comma in all three examples because the initial clauses in all three sentences precede the main clauses.
If the positioning of the clauses were reversed, a comma wouldn't be needed due to the subordinate nature of the non-main (dependent) clauses. An exception could be when trying to emphasize a significant difference such as:
He was feeling very cold today, although it was over 25C outside.
In the end, it all comes down to writing style. Very few people follow the grammar rules exactly; however, as a rule of thumb, fewer commas are always better than excess.
If the positioning of the clauses were reversed, a comma wouldn't be needed due to the subordinate nature of the non-main (dependent) clauses. An exception could be when trying to emphasize a significant difference such as:
He was feeling very cold today, although it was over 25C outside.
In the end, it all comes down to writing style. Very few people follow the grammar rules exactly; however, as a rule of thumb, fewer commas are always better than excess.