Mandarin has four basic tones, plus a fifth "neutral" tone. The same syllable can sound completely different — and mean something completely different — depending on which tone you use. Tap the speaker icon next to each example to hear it.
媽mā1st tone — flat and level
麻má2nd tone — rising
馬mǎ3rd tone — dips, then rises
罵mà4th tone — falling
嗎maneutral tone — short and light
媽媽 (māma, "mom") is a good example of the neutral tone in action: the first 媽 keeps its 1st tone, but the second one is often said lightly, as a neutral tone. Tones really matter — 媽, 麻, 馬, 罵, and 嗎 above are all the exact same sound with five completely different meanings. When you're learning Chinese, pay close attention to tones. Go slowly, practice often, and it will keep getting easier.