Does Sololearn have plagiarism check?
Humble Fool 209 for now they have no plagiarism checker for codes but we are here to check that and made them private and many community members helps us in that to find code plagiarism.
Humble Fool 209 yes if appropriate changes are made and due credit is given to the original author then user improvised code can be accepted, and the permission from the original author is too needed if the original author is ok with improvised work then they can do so
No, it doesn't. But please don't steal codes because of this
Yes, manual checks via moderators.
GAWEN STEASY Suppose one user A submits a code which is improvisation(design change/optimization: not just plain copying) of another submitted code of B. If the user A gives due credit to B in his code(comments/source/citation), will A's code be accepted?