[paradite]

Native Chinese speaker here.

I tried to tell the difference between "q" and "ch" here by pronouncing them. As the other comment noted, "ch" is actually a valid pinyin as well, so they are definitely different.

My observation is that for "q" your tongue tip is closer to your teeth and for "ch" your tongue tip is somewhere in the middle of the mouth. Hope that helps.

[ajuc]

Is this the difference between cz and ć?

https://translate.google.com/?hl=pl&sl=pl&tl=en&text=cza%20%...

Click on the speaker under Polish.

[enedil]

I'm native polish speaker and after 3 years of learning mandarin, and I need to somehow confirm, and somehow rebute. Pinyin ch is almost exactly like polish cz. Pinyin q is quite close to ć, but to make that sound you need to touch your lower teeth with your tongue. In polish the tongue stays mostly flat. There is similar difference in x vs ś and j vs dź.