Which neutral nations later joined the Central Powers/Allies in WWI?

I know for sure the original Central Powers are Germany, Austria-Hungary, and Bulgaria.

And the Allies are Russia, France, and Great Britain...

Thanks!

Check the participation of the neutral nations in this site.

http://en.wikipedia.org/wiki/Participants_in_World_War_I

In World War I, several neutral nations eventually joined either the Central Powers or the Allies. Here's how you can find out which neutral nations joined which side:

1. Research the Central Powers: Start by looking into the original members of the Central Powers, which you correctly identified as Germany, Austria-Hungary, and Bulgaria. These were the main powers that formed the alliance. Remember, as the war progressed, other countries also joined the Central Powers.

2. Investigate the Allies: You mentioned Russia, France, and Great Britain as members of the Allies, which is correct. However, the Allies comprised more nations as well. It is essential to explore the broader composition of the Alliance.

3. Consider time and events: The neutrality of some nations could change over time based on various factors. As the war progressed, circumstances and political considerations led some countries to switch sides or become involved in the conflict, whereas others remained neutral throughout.

4. Research specific nations: To find out which neutral nations joined which side, you need to research individual countries and their involvement in the war. Look for historical records, diplomatic agreements, and any official declarations of support or antagonism.

5. Consult historical sources: Access reputable sources like books, articles, or online databases dedicated to World War I history. These sources often provide insights into the actions and decisions of neutral nations during the war.

By following these steps, you can gain a comprehensive understanding of which neutral nations joined either the Central Powers or the Allies during World War I.