You should capitalize:
- The first word in a sentence
- The first word after colon if it is a complete sentence
The race was hard: The athletes had to train for many weeks
Do not capitalized:
- A person’s name that begins with a lowercase letter
van de Vijver and his team conducted a rigorous study on…
- A proper noun or statistical test that begins with a lowercase letter
iPad, eBay
t test, p value
*try to reward the sentences to avoid beginning with a lowercase letter
(Adapted from APA, 2020, pp.165)
Source
The American Psychological Association. (2020). Publication Manual of the American Psychological Association 7th edition