List of bounties with no deadline

Question

One of the problems on StackExchange sites is that questions don't always receive good answers. While unanswered questions are easy to find, this is not the case with questions that have one or more answers that don't meet the criteria of the question asker (or other members on the site).

For this reason, I am drawing some inspiration from other sites, such as Programming Puzzles & Code Golf and Puzzling:

This is a list of unofficial, deadline-less (hence not searchable) bounties offered by users on various challenges on the main site.

The list need not be limited to questions that already have an answer. You can offer bounties both for your own questions and for other people's questions.

Disclaimer: There is no guarantee that the user will award the bounty for you in case you fulfil its requirement. Especially if the user isn't an active member anymore. The only guarantee is his/her written word.

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Guidelines for updating

• To add a bounty, create an answer that contains a link to the question that needs a (better) answer and the bounty you are willing to award.
  • Answers can be sorted to see which bounties are newest.
  • Answers can be commented on, allowing someone to notify the bounty's creator that the bounty may have been earned.
• If a bounty is awarded, delete the meta answer.

Answer 1

Offering 100 for a complete answer to Is L2 fluency retention better than L1 fluency retention?, including research and citations. Note that the question itself doesn't explicitly request research, but this bounty will be awarded on that condition.

Answer 2

I offer a 100 reps bounty for a particularly good answer for What can teachers do to promote or increase mastery of 把 structures in Standard Chinese?. The question does not have any answers yet. It probably needs an answer from someone who has some experience teaching Chinese, or from a very successful learner.