Find the missing character?

H
Q
T
W

The missing character is T.

The other three characters, H, Q, and W, are all consonants that are pronounced with the tongue touching the roof of the mouth. The letter T is also a consonant, but it is pronounced with the tongue touching the alveolar ridge, which is the ridge behind the upper teeth.

The following is a table of the four consonants, with their phonetic symbols and pronunciations:

| Letter | Phonetic symbol | Pronunciation |
|—|—|—|
| H | /h/ | /h/ as in “hat” |
| Q | /k/ | /k/ as in “cat” |
| W | /w/ | /w/ as in “wet” |
| T | /t/ | /t/ as in “top” |

As you can see, the only consonant that is not pronounced with the tongue touching the roof of the mouth is T. Therefore, T is the missing character.