[tlhIngan Hol] Why can't I say..

[mayqel qunenoS]

Assume I want to write: "many years I've been tickling the cat".

If I stop and think, what most people here are expecting to see, I
then I would write:

{qaStaHvIS DIS law' vIghro' vIqotlh}.

However, I really can't see the reason why I cannot write:

{DIS law', vIghro' vIqotlh}.

Is this wrong ? And if it is, could someone be so kind as to explain why ?

qunnoH jan puqloD