Spoken Mandarin is virtually always spoken with tones (except when sung, or when foreigners speak it), but when written virtually never has tones (e.g. signs).

Spoken Mandarin is virtually always spoken with tones (except when sung, or when foreigners speak it), but when written virtually never has tones (e.g. signs). Only childrens books write the tone marks. So, along with various other intonation, there's a lot more information communicated during speech.