How to differentiate benevolent and malevolent spirits
Are you really talking to your spirit guide or are you facing an impostor?
This is such an important question and I love when my clients ask it to me because it shows their will and dedication to learning about energies and trusting themselves!
Keep reading for more info that will help you distinguish benevolent and legit spirit guides from malevolent spirits who are impostors and trying to trick you.

2 types of energies and vibrations
I don't use the terms "good" or "bad" spirits because it is important not to give in to judgment.
When I refer to spirits, as a shaman, I prefer using these 2 words
"benevolent" = a spirit who has intentions that serve your highest good
"malevolent" = a spirit who has intentions to serve his/her own agenda and that doesn't serve your highest good.
Like I said, it is important to let go of judgment, because a spirit that vibrates at a low frequency is not necessarily malevolent in that sense that it doesn't necessarily want to harm you.
Compare it to a human being, someone who has a negative mindset or who is pessimistic is not a "bad human" who has "bad intentions".
See the difference?
Detaching from judgement of "good" and "bad" is the 1st step in clearing your mind so you can differentiate the benevolent from the malevolent spirits more easily.

Signs of a benevolent spirit
has a positively high vibration
never intends to scare you
means no harm
feels light and peaceful
never wants to manipulate you
respects your free will
will never try to trick you
comes to you spontaneously to bring help, peace, relief, comfort...
you can smell a pleasant and subtle etheric smell (ex: flowers, a perfume)
etc.
Signs of a malevolent spirit
has a negatively low vibration
can intend to scare you
means harm
feels heavy, dense
is manipulative
doesn't respect your free will but uses trickery to get you to consent
might come spontaneously but can also come as an impostor when you're calling upon your spirit guides or deceased loved ones and pretend to be them
you can smell an unpleasant smell (like rotten eggs...)
etc.

What to do to make the distinction between benevolent and malevolent spirits
Observing without reacting would be my 1st advice
Use discernment
Know yourself and your reactions: your body language (tensions, goosebumps...), your mental patterns (ex: sudden racing thoughts, old fears coming up...), your emotional response (ex: mood swing after a spirit manifested its presence...)
Awareness of your triggers and wounds
Trusting yourself: if something doesn't feel good, then it's not, even if the being in question tells you they're a deity, if it feels sketchy, don't trust them
Never engage in a "conversation", especially if you're unsure of who they are
These are basic tips that can help you.
If you're ready to learn more about yourself, dismantle your fears, deactivate your triggers and have effective and efficient techniques, my teachings will provide you with all of that (and more!).
I'm inviting you to check out my beginner's course:
"How to protect yourself from toxic energies to improve your life"
Side note: I made it very accessible to everyone (although the content's value is worth at minimum 3 times more) because I consider that more people should have relevant and reliable information about these things from people who have studied these things, like myself and other legit shamans.