Emaelivpeith Estel Telcontar:
>How would "I saw Janny [and it actually was her]" look,
>and how would " I "saw" Jenny [but it was actually someone else]" look?
>And how would "I "saw" Jenny, [but I'm still not sure whether or not it
>really was her]" look?

Ah, the translation opportunities!  :)  The normal, everyday version of the
sentence is:

    KÚnillevpeni ne Jeni.
    I saw Jenny.

On to the unusual versions:

    KÚnillevpeni ne Jyeni.
    I saw Jenny, but she was not herself at the moment.

The |-y-| infix marks something as not being its true self.  When applied
to a person, it means that it was physically that person but they weren't
"in their right mind" or "not themselves today."  Think of your usually
mild-mannered Jenny who been having a very bad day, and you happened to
drop the last straw and so she blew up at you.  That was Jyeni, not Jeni,
who just chewed you out over putting an extra sugar cube in her tea.

    KÚnillevyopeni ne Jeni.
    I thought I saw Jeni, but I didn't actually see her.

The same infix can also apply to verbs.  Whatever an action normally
entails, its |-y-| version doesn't live up to its average definition.
Here, it means that you somehow didn't really see Jenny.  This would
usually be interpretted to mean that you saw something (perhaps a person,
perhaps not) out of the corner of your eye that gave you the impression it
was Jenny, but when you turned to get a better look you saw that it wasn't
actually her.

Your middle example, "I 'saw' Jenny [but it was actually someone else],"
didn't have a way of being expressed in Asha'ille, so I remedied that.  :)

    KÚnillevpeni ne kr'Jeni aerdhisa.
    I saw someone who I thought was Jenny but was actually someone else.

This translation takes advantage of serial objects.  Both |kr'Jeni| and
|aerdhisa| are objects of the verb, but context makes it clear that the two
words actually describe the same object.  Since that is the case, the first
word is understood to be what you saw, and the second word a clarifier.

Compare that with:

    KÚnillevpeni ne aerdhisa kr'Jeni.
    I saw somebody, but it wasn't Jenny.

Here, you knew from the beginning the person wasn't Jenny.  In this usage,
you're just clarify that, no, the person was someone other than Jenny.

An example of a case when two serial objects describe two separate items:

    KÚnillevpeni ne chodßl uruman.
    I saw the food (and the) water.

It makes more sense for this to mean that you saw two things -- food and
water -- rather water that doubled as food.  If the second meaning was what
you intended (nutrients in the water, like an IV perhaps), you'd have to
explain in more detail.

Luckily, I don't think this will cause ambiguity with objects modified by a
single adjective, which comes before the noun.  For example:

    KÚnillevpeni ne uyan uruman.
    I saw the blue water.

|uyan| "blue" can't be a noun, so this can't be mistakenly understood as "I
saw a blue thing and some water."  Whew.  :)  (Of course, some ambiguity
adds to naturalism...)