(_a_) The root always ends in a long vowel.
(_b_) There is no change of consonants.
(_c_) The third person sing. of the present tense is the simple root.
(_d_) The last vowel of the root is liable to changes before the =i= of
the past tense and conditional.
(_e_) In the present passive, and in infinitive I the termination =ta=
becomes =da=.