There are four tones in speaking Mandarin:
1. First tone is a high and level sound with the volume held constant, as in the word mā 妈 https://chinesecharacteraday.com/wp-content/uploads/2011/01/Ma-1.mp3 which means mother. The symbol of the first tone’s pronunciation is a straight line — placed above the pinyin of 妈 MĀ.
Note that the word for mother 妈 has the symbol for woman 女 on its left and the symbol for 马horse on its right.
2. Second tone rises from middle register and increases in volume, like the pronunciation of a surprised `Me?’ As in the character má 麻 https://chinesecharacteraday.com/wp-content/uploads/2011/01/Ma-2.mp3 which means numb. The symbol of the second tone’s pronunciation is a straight line slanting upward from left to right / placed above the pinyin of 麻 MÁ.
3. Third tone starts low, then falls lower before rising to a sound higher than the starting point. As in the character mă 马 https://chinesecharacteraday.com/wp-content/uploads/2011/01/Ma-3.mp3 which means horse.
The symbol of the third tone’s pronunciation is a v placed above the pinyin of 马 MĂ.
4. Fourth tone starts high, then drops sharply, like saying `fine’ when agreeing to an order. As in the character mà 骂 https://chinesecharacteraday.com/wp-content/uploads/2011/01/Ma-4.mp3 which means to scold. The symbol of the fourth tone’s pronunciation is a short line slanting downwards \ from left to right placed above the pinyin of 骂 MÀ.
Note that the three characters 妈 马 骂 all contain the radical 马。 Their pinyin is MA for all of them but a listener is able to differentiate between them because of their different tones.