Learn Hardcore Finnish: Koira on pieni.

Finnish does not have articles the way English does. In other words, there is no separate word to indicate whether something is definite (the dog) or indefinite (a dog). Instead, context or other parts of the sentence help convey whether the meaning is definite or indefinite.

Why is the adjective "pieni" in its base form here?

In Finnish, adjectives agree with the nouns they describe in case and number. Since "koira" (dog) is in the nominative singular (the basic form meaning it’s the subject of the sentence), the adjective uses its own nominative singular form, which is pieni.

Do I need to add any special ending to "koira" to show it’s the subject?

No, you don’t. In Finnish, the nominative singular form of a noun is often the same as the base dictionary form (for example, "koira"). This is enough to show it’s the subject when it’s placed in front of the verb.

Can I change the word order in "Koira on pieni"?

Yes, Finnish word order can be flexible. However, the typical pattern is Subject–Verb–Complement. If you want to emphasize different parts of the sentence, you can change the order, but as a beginner, it’s best to stick with the basic order.