You might not differentiate too well with "shi" and "si" pinyin in mandarin if you are not a native speaker. Or maybe you pronounce "she" differently. There shouldn't be a "sh" sound in "xi".
I'm a native speaker; my first language was Mandarin.
On the other hand, I'm a Southerner, so I don't usually distinguish between "sh" and "s" sounds. I can do the 卷舌 thing, though, well enough that Northerners tell me I'm doing it right, and I don't think either Pinyin "shi" or Pinyin "si" sound anything like English "she". And while I don't think Pinyin "xi" sounds exactly like English "she", I think it sounds pretty close.
... in the vernacular. Proper pronunciation is more like “she”.
This is an issue lost on most native speakers of mandarin, and it’s hard as hell to teach to learners.
pinyin —> proper sound —-> actual sound
xi —> she —> see
si —> suh —> suh
shi —> shuh —> suh
chi —> chuh —> tsuh
ci —> tsuh —> tsuh
There are more, but I’m too many beers in now to remember.
The best test is to ask someone how to say 四十四是四十四 (44 is 44). It’s a good test for tones. This is properly something like /shuh suh shuh shuh shuh suh shuh/. In vernacular, this usually becomes something like /suh suh suh suh suh suh suh/ with tones being the only hint at different words.
In standard Beijing Mandarin pronunciation? If you have a dialect then you might have stronger "sh" sound when trying to pronounce "si" "ci" "zi" "xi", so it's hard do differentiate between "si" and "shi", "ci" and "chi" or "zi" and "zhi". 四是四，十是十，十四是十四，四十是四十。
I humbly suggest that Beijing Mandarin pronunciation is not “standard” putonghua — otherwise, mostly of these sounds would end with a retroflex /r/.
I forget the details now, but “standard” putonghua has two variants, and each variant revolves around Jiangsu province (something like north and south?). Anyway, Beijing people think that they speak the “standard”. People educated in linguistics know better.
I beg to differ. Read here: "Its pronunciation is based on the Beijing dialect, its vocabulary on the Mandarin dialects, and its grammar is based on written vernacular Chinese."
No, just give up trying to find that sound in English, it basically does not exist. Apparently Cantonese is a lot easier for English speaker to learn, they don't have these special phonemes.
And to me, Mandarin 'xi' sounds a lot more like "she" than "see".