There are always areas of one language that native speakers of another have trouble with either because their language lacks certain phones, combinations of phones into phonemes, or phonotactics.  For example, the French-German “r” is lingual-uvular fricative, while, in Spanish-Italian, it is a apical-dental trill, and, in English, it is lingual-alveolar.  The Chinese “r” is actually similar to the French-German unless it is the final sound of a phoneme, like “er”.

Sometimes a problem is in the phones, the basic sound that are part of a language or not.  A common example of that it the lack of either a voiced or unvoiced “th” sound, in the French language.  In that regard, French speakers usually replace the voiced “th” with a “z” sound and the unvoiced “th” with an “s” sound when speaking English.  The same is true for that phone, in Chinese.  Even with French speakers of English from places, like Quebec province, in Canada, or Cameroon, in Africa, where both languages are official languages, French speakers speak with a discernable French accent of English.  Another example is the Russian, “shch”, which is not available, in normal English, but is not too difficult for English native speakers to access.  In Chinese, there is an absence of several phones.  There is no “zh”: their “zh” is more like a “dzh”, so there is difficulty for a native Chinese speaker with words, like “usually”.

The next problem is phonemes.  Some phonemes are not available, in a particular language, even if the phones are.  For example, in Italian, most phonemes end with a vowel, so that Italian speakers of English tend to add an extra vowel at the end of English words, even though they are not there.  That has to do with what are called phonotactics, which sets the rules for consonant clusters, vowel clusters and syllable formation.  Further rules, in phonotactics, have to do with internal segmentation of syllables, looking at an onset, nucleus and a coda.  In that regard, some clusters or sounds are allowed in, for example, the onset but not the coda or vice versa.  For example, “ls” is available, in English, in codas but not in onsets.  In Chinese, while vowel codas are common and numerous, the only consonant combinations available in codas are “n”, “’r”, and “ng”.

As a result, Chinese speakers, when speaking English, tend to leave off most final consonants, in spoken words.  Thus, “what do you want?” becomes “wa do you wan”, and “I hate it” is pronounced “I hay ĭ”.