|Shash tshinipati tekushinian.||You were already asleep when I arrived.|
The Independent Indicative Past conjugation (#03), like the form tshinipati above, is used for things that happened in the past.
|Shash nipapan ka takushinian.||S/he was already sleep, when I arrived.|
It can be used with the modal preverb tshipa.
|Shashish an tshipa tshitutepan uipat aieshkupitakue.||S/he would have left if I had arrived.|
It can be used with the volitional preverb ui.
|Shash tshui nipati …tekushinian.||You already wanted to sleep / You were about to sleep …when I arrived.|
|Shash ui nipapan …tekushinian.||He already wanted to sleep / He was about to sleep …when I arrived.|
|Shash an tshipa ui tshitutepanat utakushit.||They should have already left yesterday.|
More on preverbs…
Link to the conjugation guide.