Chinese vs Cantonese
How to tell Chinese from Cantonese
Mandarin and Cantonese are both Chinese (Sinitic) languages that share most of their characters and a formal written standard, but in speech they are not mutually intelligible: Cantonese has six tones, different everyday vocabulary and grammar particles.
The short answer
Listen for endings: Cantonese keeps clipped -p, -t and -k finals (十 sap6) and has six tones, while Mandarin (十 shí) has none of those finals. In writing, colloquial Cantonese uses characters such as 嘅, 唔 and 係, where Mandarin texts use 的, 不 and 是.
The verdict
Written text with 唔, 嘅, 咗, 喺, 係 is Cantonese; Simplified characters mean Mandarin (Hong Kong uses Traditional).
Closeness score
20 / 30
Mutually intelligible?
partly
Shared vocabulary
Formal vocabulary is largely shared; everyday spoken vocabulary diverges considerably
Which first?
Mandarin first unless you live in Hong Kong / Guangdong.
Kungfucius says: Same family dinner, different dinner-table language.
Side by side
chī食
sik6食 is the older word (Classical Chinese); Mandarin replaced it with 吃 in everyday speech but keeps 食 in compounds such as 食物.
bù / de唔 / 嘅
m4 / ge3These characters exist almost only in written Cantonese, so their presence identifies the text immediately.
shì係
hai6Cantonese uses 係 as its everyday copula; Mandarin uses 是.