O: When pronouncing, the lips are round, slightly warped, the tongue retracts, the back of the tongue is upturned, the tongue is centered, and the vocal cords vibrate.

Ao: when pronouncing, pronounce A first, then retract the tip of the tongue, lift the base of the tongue up, wrap around the mouth and gently slide to O.

O: When pronouncing, the O sound is pronounced first, the lips gradually converge, the tongue base is raised and then the U sound is pronounced, and the mouth shape changes from a big circle to a small circle.

Ong: When pronouncing, pronounce O first, then the base of the tongue retracts against the soft palate, the tongue surface protrudes, the lips are round, and the nasal cavity resonates into a sound.

Spelling method:

1, phonological spelling-spelling vowels as a whole with initials. Such as: h-ao→ (Hao).

2, the initial two spelling-first find the pronunciation part of the initial, set the pronunciation posture, and then read the vowel in one breath and spell it into syllables.

For example, to spell bā (ba), first close your lips, hold your breath, put on the sound of b, and then pronounce a syllable in one breath.

3. Three-syllable linking method-that is, the syllable with intermediate sound is analyzed into three parts: sound, middle and rhyme, and read into one syllable with pinyin.

Such as: q-I-ang→qiáng (strong).

Refer to the above? Baidu encyclopedia-hanyu pinyin

Refer to the above? Baidu encyclopedia-pinyin