T.
T has its customary sound; as take, temptation.
Ti before a vowel has the sound of si as salvation, except an s goes before, as question; excepting likewise derivatives from words ending in ty, as mighty, mightier.
Th has two sounds; the one soft, as thus, whether; the other hard, as thing, think. The sound is soft in these words, then, thence, and there, with their derivatives and compounds, and in that, these, thou, thee, thy, thine, their, they, this, those, them, though, thus; and in all words between two vowels, as, father, whether; and between r and a vowel, as burthen.
In other words it is hard, as thick, thunder, faith, faithful. Where it is softened at the end of a word, an e silent must be added, as breath, breathe; cloth, clothe.