त (ta) series

For the next series of letters, the tongue is placed behind the teeth for another series of "t", "d", and "n" sounds.  In English, the tongue is usually put on the ridge above the teeth.  Hindi also has "t" and "d" sounds where the tongue is placed at the top of the mouth (retroflex).

The first letter is त (ta).  It does not have a puff of air (aspiration) after it:

Yo

The next letter is थ (tha), which does have a puff of air after it:

Yo

The letter थ will cause a break in the "clothesline" from which the Hindi letters hang, as in साथ (with):

 

Next is the letter द (da), which has no aspiration (puff of air):

Yo

Next is the letter ध (dha), which has aspiration (puff of air):

Yo

Note that like the letter थ above, ध will cause a break in the "clothesline" from which the Hindi letters hang, as in the word आधा (half):

The last letter in this series is न (na), which is a nasal.  This nasal sound will occur followed by a vowel, as in नान (naan):

 

Yo