Four tones of Chinese Mandarin:

Macron ( ˉ ):

In Pinyin, the official Romanization of Mandarin Chinese, macrons over a, e, i, o, u, ü (ā, ē, ī, ō, ū, ǖ) indicate the high level tone of Mandarin Chinese. The alternative to the macron is the number 1 after the syllable (for example, tā = ta1).

Acute Accent ( ´ )

The Pinyin romanization for Mandarin Chinese, the acute accent indicates a rising tone. The alternative to the 

Caron ( ˇ ) :

The caron indicates the third tone (falling and then rising) in the Pinyin romanization of Mandarin Chinese. It looks similar to a breve, but has a sharp tip, like an inverted circumflex (ˆ). The alternative to the caron is the numberal 3 after the syllable: bǎ = ba3

grave Accent ( ` )

The grave accent is used to indicate a falling tone. The alternative to the grave accent in Mandarin is the numeral 4 after the syllable: pà = pa4.