You might want to share your achievements with the scientific community. Therefore Research Gate offers many tools, but legal problems might be present.
Question: Can I upload the PDF of my paper to Research Gate?
Answer (Head of Institute): Only if you published open access. Otherwise NO!! Legal problems….
Answer (Co-Worker): Yes of course. Maybe you can just upload the preprint (the MS as WORD File in the latest version).
Answer (your best friend): Yes of course. Don’t care about copyright. We are living in a free world. A PDF of the printed version is fine!!
These answers might be initially of help but are highly depending on the person you ask. A more reliable information is given on SHERPA ROMEO. For every publisher, journal, etc. the regulations are summarized and you can look up if your decision on upload was fine. You should do this in advance since the WWW does never forget any shared item.
Happy sharing, Jürgen