Summary

| override_editor Encyclopædia Britannica, Ninth Edition…

But the term "dental" includes some varieties of position, of which the most definite are— (1) where the point of the tongue touches the teeth (true "dental") , as in French; (2) where the tongue touches the gum behind the teeth, and not the teeth at all, as in English; (3) where the point of the tongue is slightly bent back against the palate, producing the sound much heard in south India (often called "cerebral") . T when followed by I or y is liable to pass into the s-sound
Source: Wikisource

| override_editor Encyclopædia Britannica, Ninth Edition…

T is the twentieth symbol in our alphabet. It has varied but little in form since the earliest days when it appeared in Greece and Italy, though some of the Italic alphabets exhibit variants: e.g. in Umbrian and Etruscan inscriptions we find the horizontal stroke sometimes on one side only, and slanting; sometimes the form is nearly that of our ordinary small t without the ornamental turn at the bottom.
Source: Wikisource

| override_editor Encyclopædia Britannica, Ninth Edition…

The nature of the two sounds is this: the tongue is pressed against the back of the teeth (sometimes, especially when used by foreigners, against the bottom of the upper teeth) and either the breath for th or the voice for dh is forced through the interstices of the teeth. This pair of sounds is found in modern Greek, where th appears as θ and dh as δ. In Spanish and in Danish under certain circumstances the sound denoted by d is dh.
Source: Wikisource

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