Old Thean

Recall T1 S T2 V O. In Old Zzean, T2 becomes cliticized or lost. In Early Old Zzean, T1 is the only word that inflects in a sentence.

In later OZz, T1 becomes an invariable tense or discourse particle

A T1 particle of some sort might be mandatory in Classical Zzean but not in Modern Zzean