What are the tax etc. implications of giving a friend's company an interest free loan? has been marked as a duplicate of question How do you declare an interest free loan?, however, the former involves lending money for [to] a business. Since the entity to whom the loan is made is significantly different there are answers to one that would not apply to the other; my own answer would refer to taking equity in the company and the tax and personal finance differences resulting from taking equity in the firm over lending at a non commercial rate. That answer also covers both effects on the firm's and the lender's finances. Since there is a different legal status of the recipient in each case and the posters care about the recipient as an entity differently can we not say that these are not duplicates?
Regardless of the problems of the original question, this will occur from time to time where a question is asked that's more-or-less identical to another.
The correct process that should follow is that it should be marked as a duplicate; and then, if the original poster agrees, left alone. If the original poster does not feel the other post answers his/her question, they should either edit the question to more specifically address that issue, or ask a new question if needed (if it's too big of a change).
For example, take the following "original" question:
If I loan some money without interest (but expecting payment) to someone, does it constitute a gift?
And then the following second question:
If I loan some money without interest (but expecting payment) to my brother, does it constitute a gift?
Those are basically duplicate questions, assuming the second is no more specific than that. The second should be marked as a dup. Then, if the OP is specifically asking "Does the fact that it's my brother make a difference?", then the question should be edited (or a new question opened):
Is a loan without interest to a family member treated differently than a loan without interest to a non-family member?
Of course, the original question may include answers that cover the different kinds of loans, in which case the OP hopefully got their answer and moved on.