Learn Finnish: Ennen kaikkea haluan oppia puhumaan suomea. - Above all, I want to learn to speak Finnish.

The word ennen (before) acts as a preposition here. In Finnish, prepositions generally require the word that follows them to be in the partitive case. Therefore, kaikki (everything) becomes kaikkea, making the set phrase ennen kaikkea literally mean "before everything".

Why do we use the form puhumaan instead of the basic dictionary form puhua?

This is due to verb rection, which is the rule of one verb demanding a specific form from the word that follows it. The verb oppia (to learn) always requires the next verb to be in the third infinitive illative form, ending in -maan or -mään. You can think of it as learning into doing an action.

How do the grammar rules work when chaining three verbs together like haluan oppia puhumaan?

In a Finnish verb chain, each verb only dictates the form of the verb immediately following it. The first verb, haluan, requires a basic first infinitive (oppia). Then, oppia takes over as the "boss" of the next verb, requiring that -maan form (puhumaan). You just apply the rection rules step-by-step from left to right.

Why is the language in the partitive case (suomea)?

The verb puhua (to speak) describes an ongoing action that doesn't have a clear endpoint. Because speaking a language is seen as an unbounded process rather than a completed task, its object must always be in the partitive case.