to, chto

[Loren A. Billings]

Emily,

It was nice to meet you at AATSEEL.  I wish to add briefly to George's
excellent answer.  Note that verbs which assign an oblique case do not
have the option of doing without _to_:

1.  I vladeiu tem, chto tebe nuzhno.  'I possess what you need.'

This is because that oblique case-assignment must be discharged.  With
certain accusative-assigning verbs (for various reasons, there has to be
an overt acc-case object):

2.  I izuchaiu (*matematiku).  'I study (= am majoring in) math.'
3.  I prochitaiu (*tvoiu knigu).  'I will read(-through) your book.'

[* within parens means "cannot be left out']

I would suspect that these verbs, too, require _to_ as well:

2'.  I izuchaiu (*to), chto vy prepodaete.
3'.  I prochitaiu (*to), chto ty napisala.

The optionality you see has to do with certain verbs that can take either
a noun-phrase or *clause* as its complement (i.e., none of exx. 1-3
above).  These are what George is discussing.

These are my somewhat half-baked responses.  This is not what I do
primarily, but none of this seems to be controversial.  Best,  --Loren