I was told most countries are masvuline, but feminine when ending in e
The largest category of countries in French are feminine ones. Those ending in 'ie' are normally feminine because of their latin root 'ia'.
Often, when a country ends in a consonant, it will be masculine but not always, you may find exceptions to all of these rules.
Here are some examples of countries who might appear to be feminine but are in fact masculine.
Le Mexique, Le cambodge, Le Mozambique, Le Vénézuela, Le Nicaragua etc...
Hope this helps!
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