Phonetics
1. Initials: zh ch sh r
Finals: ai uai ong
2. Third-tone sandhi
A third tone, when followed by a first, second or fourth tone, or most neutral tone syllable, usually becomes a half third tone, that is, a tone that only falls but does not rise. The tone mark is unchanged.
3. Tone sandhi of “不”
不 is a fourth tone syllable by itself. But it becomes a second tone when followed by a fourth tone.
Key Points
1. Ask a person`s occupation and nationality.
她/他是哪国人？（tā shì nǎ guó rén?）What’s her/his nationality?
她/他是中国人。（tā shì zhōng guó rén） She/he is a Chinese.
2. Introduce friends, family and others.
Introduce someone to a person, we use “这是……”