How to pronounce 學 "shwehh", "shoo-ehh", or "xüüehh"?
I must say that the differences are not negligible to Chinese people, because they won't have a &quot;sh&quot; followed by &quot;w&quot;, and that's not the same problem as &quot;where ya goin&quot;.
To your first problem, I think it's because you're still not skilled enough to pronounce &quot;x&quot; (because this consonant is absent in English, French, and many European languages, and people often use &quot;sh&quot; to replace it). If you really feel hard to go this way, choose &quot;sy&quot; or &quot;xi&quot; instead of &quot;sh&quot;, like &quot;sy-ü-ehh&quot;, and slowly progress towards the correct &quot;xue&quot; (note that in Pinyin orthography, the umlaut is omitted).
EDIT: I answered this question based almost on instinct at that time. I'll explain more about it now.
Modern Mandarin pronunciation was finally set during early 1910s with one last big change: the &quot;merge&quot; of jianyin (lit. &quot;sharp consonant&quot;) and tuanyin (lit. &quot;round consonant&quot;). Since then, consonant /z/, /c/ and /s/ cannot be followed by /i/ or /ü/, only their counterpart /j/, /q/ and /x/ can (e.g. /sing/ and /xing/ were different before this change, but then they merged into /xing/. Note that this merge does not apply to some topolects). Therefore, it is much easier for learners to imitate /xi/ or /xü/ from /sy/ or /sü/ instead of /shy/ and /shü/. You just need to lift the middle of your tongue to the upper gum from /s/ to pronounce it.