You should read this
Post:256204. Here is just a part of it:
There are a number of particles (
up, down, in, out, on, off, away, back) which should make us very suspicious that we are dealing with a separable phrasal verb, and a number of them (
with, without, by, for, at, across, of, from, to, into) which almost certainly indicate a prepositional verb. But there are some strange cases!
_____
<>a. Pick up it (INCORRECT)
Phrasal verb pick up. Object it must precede up.
b. Pick it up (correct)
c. Pick up the phone (correct)
d. Pick the phone up (correct)
Example two:
<>e. Looking at it (correct)
f. Looking it at (INCORRECT)
Prepositional verb look at. Object it must follow at.
g. James handed in the report (the report is "it") (correct)
h. James handed it in (it is "the report") (correct)
i. James handed in it. (INCORRECT)
Phrasal verb hand in. Object it must precede in.
CJ