Phrasal verbs

I was wondering if there is any specific explanation to differentiate separable and non separable phrasal verbs. It's about an English class. Thanks in advance for any answer

Hmmm . . .

Plenty of viewings; no replies. I am familiar with phrasal verbs, but the two terms don't help. Post a couple of examples -- always offer examples because one of the great difficulties that teachers face is that pedants over centuries have re- and re- and re-termed the identifiable dynamics of English until even the best teacher in the world feels as though she is drowing in indeterminate terms.

Inseparable- look into (you can't put anything like a pronoun between the verb and particle)
Separable- Put it away (you can)

I am afraid that this is basically a question of looking in the dictionary- there's no explanation that I know of.