Final answer:
The three capitalization errors have been corrected in the sentence.
Step-by-step explanation:
The three capitalization errors in the given sentence are:
- The word 'person' should be capitalized as it is the beginning of a sentence.
- The word 'senator' should be capitalized as it is a specific political title.
- The word 'constitution' should be capitalized as it refers to a specific document.
The corrected sentence should be:
According to the Constitution, a person must be at least thirty years old to serve as a senator.
Learn more about capitalization errors