Conversation so far:
What is the religion of the Sinhalese people ?
The form of Buddhism in Sri Lanka is known as Theravada.
How many of the Sinhalese people are Buddhists ?
In 1988 almost 93% of the Sinhala speaking population in Sri Lanka were Buddhist.
For the remaining 7%, What religions do Sinhalese people also believe in besides Theravada buddhism?
There is a significant Sinhalese Christian community, in the maritime provinces of Sri Lanka.
Any other religions they believe in besides Buddhism and Christianity?
Prominent Sri Lankan anthropologists Gananath Obeyesekere and Kitsiri Malalgoda used the term Protestant Buddhism to describe a type of Buddhism that appeared among the Sinhalese in Sri Lanka
Are there any other interesting aspects about Buddhism in Sri Lanka besides the different types of Buddhism and the large percentage of people who subscribe to Buddhism?
Due to the proximity and on some occasions similarity of certain doctrines, there are many areas where Buddhists and Hindus share religious views and practices.
Which traditions did Buddhists adapt from Hindus ?
Some of these practices adapted from Hindus may relate to ancient indigenous beliefs and traditions on spirits, worship of deities and godlings and some figures appear to demons.

Question: Did they adopt anything from Christianity?
Self-contained rewrite: Did Sinhalese buddhists adopt anything from Christianity?