I don't know whjy it took me so long, but I just thought of this example of multiple tones for the same syllable in a single sentence.
Check this out. How would you say "Did your mother scold the horse for eating hemp?" in Mandarin?
你妈骂吃麻的马吗？
nǐ mā mà chī má de mǎ ma?
There are actually five tones in Mandarin, not four, because there is a no-tone variant as well.
This sentence has them all.
妈 mā (high tone) means "mother"
骂 mà (falling tone) means "scold"
麻 má (rising tone) means "hemp" (it could also mean "numb")
马 mǎ (falling-rising tone) means "horse"
吗 ma (no tone) is a question particle used to convert a statement into a question.
吃麻的马 chī má de mǎ means "a horse that eats hemp"
Chinese grammar is dead simple. Recognising characters is only slightly hard. Tones are subtle and relatively hard to master. Writing characters is probably the hardest of all. However, most apps today allow one to write in 拼音 pīnyīn (Roman) and select the right Chinese character.