Usage of olvidar alone, in the reflexive and with or without "de".

Question

Three ways of using the verb olvidar are presented in this exercise: olvidar, olvidarse and olvidar de. What is (are) the general rule(s) regarding its usage and is one way more commonly used generally, or in different countries, or more preferable grammatically under different circumstances?

Accepted Answer

Hola Gerald
Here is a lesson about the different ways to use olvidar, where you will be able to see lots of examples.
It's really the choice of the speaker with the option using olvidarse de... being, I would say, a more relaxed/common way to use it. For me, olvidar [algo] sounds a bit more formal and the pronominal form (olvidarse de [algo]) is more common to hear. 
The third option is the accidental "se" form that we use more when we want to convey that it's "not our fault" but be careful here because in this case you need to conjugate the verb agreeing with what is forgotten, not the person:

¡Se me han olvidado las llaves!
I forgot the keys!

I hope this and the lesson clarifies it.
Saludos
Inma

Answer

Muchas gracias.

Answer

Are there other verbs that is similar with olvidar where 3 forms of usage have the same meaning ?