Mandarin: ao, a

I never realised the difference between a, like 阿, and the a sound in ao, like 凹, in Mandarin. I mean, I always know this. I always know how to pronounce a and ao correctly. I just never broke the diphthong and compared the a- with a, until a few months ago.

Briefly, the pronunciations of the two sounds are as follows:

• a (ㄚ): [a]
  The a (ㄚ) in Mandarin is different from the a like ah in English. To make this [a], you have to break the diphthong [aɪ], like I and eye, into separate parts, and elongate the first part, [a], as long as you can, and drop the remaining part.
• ao (ㄠ): [ɑʊ] (the [ɑ] is longer than [ʊ] here)
  This ao sound is different from that ow sound in English, like out and cow. Ow in English is pronounced this way: [aʊ] (Actually, I don’t know if I am 100% correct, the [a] in [aʊ] is a bit palatalized nowadays.) But the pronunciation of ao in Mandarin is [ɑʊ]. I am sure you know how to make these two sounds: [ɑ] (ah) and [ʊ] (the ou in would). So, I think I can leave it to you here. Just make sure the [ɑ] is much longer than the [ʊ].