New language- Rhêndrin

Yes, yet another Sindarin-esque language.

Over christmas got a Gaelic grammar, and I was toying with an idea for an
"elvish" language for the people north of Cendos. So, I created an
agglutinating parent language, Teinasen from odds and ends of a load of old
abandonend conlanging projects and derived Ðweinaren and then Rhêndrin from
it.

Really, the only aspect of Rhêndrin grammar I want to run by you is the
periphrastic formastion of the present tense. As in Scottish Gaelic, verbs
do not have an independant present tense, instead it is formed with the verb
to be followed by the preposition e "to" (always followed by the accusative
of subject), the genitive of the object and the verb in the present
participle:

Tâ eir maw i thorna n-yth /ta: eIr mau i 'Tornan@T/
Is to-the sheep(acc) the grass(gen) eating.
The grass's eating is to the sheep. OR The sheep is eating the grass.

A chaerbel i rhodhen, tuith edh i mbârcha mbest?   /a xa'Erb@l i RoD@n, twiT
eD im'ba:rxamb@st/
INT would-run the queen, was to-her the lady(gen) seeing?
Would the queen run, if the lady's seeing was to her? OR Would the queen run
if she saw the lady?

Are there any other conlanging examples of this sort of thing? I know it's
quite common in the celtic languages.

Dan