Learn Finnish: Se ei merkitse sotaa.

merkitä is a Type 5 verb (verbs ending in -ita or -itä). To find the base form (stem) for these verbs, you remove the final -tä and add -tse. This gives us the stem merkitse-.

Why doesn't the verb have a personal ending here, like merkitsee?

In Finnish negative sentences, the negative verb (ei for 'it') does the heavy lifting. The main verb drops its personal ending and takes a special base form. For Type 5 verbs, this form is exactly the same as the -tse stem, so it is just merkitse.

Why is the word for war sotaa instead of just sota?

sotaa is in the partitive case. A major rule in Finnish is that if a sentence is negative, the object (the thing receiving the action) must be in the partitive case. To make sota partitive, we simply add an -a to the end.

Does merkitä always mean 'to mean'?

It often translates to 'to mean' or 'to signify' in contexts like this one. However, it can also mean 'to mark' (like marking a test) or 'to matter' (for example, se ei merkitse mitään means 'it does not matter').