1 Serron: How did a planet get to be entirely French-speaking, anyway?
2 Paris: Well, it was colonised by early French space explorers.
3 Paris: In fact, the way French law works, technically the whole planet is actually still an integral part of France.
4 Serron: Jean-Luc Picard, you have a lot to answer for.

How many countries does France have a land border with?

Answer: Eleven.

Belgium, Luxembourg, Germany, Switzerland, Italy, Monaco, Spain, Andorra, Netherlands, Brazil, and Suriname.

French Guiana, which is in South America and borders Brazil and Suriname, is an overseas department of France, which has exactly the same legal and governmental status as regions of mainland France. It is in every sense part of France, rather than a legally distinct overseas territory such as some other countries have. French Guiana is a part of France in the same way that Alaska and Hawaii are part of the USA, or Tasmania is a part of Australia.

The Caribbean islands of Guadeloupe and Martinique, and the Indian Ocean islands of Réunion, and Mayotte are also integral parts of France, but they don't contribute any land borders.

However, the Caribbean island of Saint Martin is divided between the French Collectivity of Saint Martin and the Dutch constituent country of Sint Maarten. Although the French side does not have the same political contiguousness with France that French Guiana has, the border is still considered an international land border, thus providing the only place in the world where France borders The Netherlands.

France also has several other overseas territories, which have various different legal/political statuses, including some level of self-government in some cases. (Think Guam or American Samoa for the USA, or Christmas Island or Norfolk Island for Australia.)