Learn Hardcore Finnish: Aion lainata kirjan, jonka jokaisella sivulla on kaunis kuva. - I am going to borrow a book that has a beautiful picture on every page.

Aion is the 1st person singular present tense of aikoa (“to intend”). Finnish doesn’t have a separate future tense, so the present tense (often with aikoa) carries future meaning.
• aion = “I intend” or “I’m going to”

What does lainata mean—“to borrow” or “to lend”?

Lainata can mean both, depending on context.
• If the subject receives something, it means “to borrow.”
• If the subject gives something, it means “to lend.”
Here, minä (the speaker) is borrowing, so it’s “to borrow.”

Why is kirjan in this form (with –n)? Is this the genitive or the accusative?

In Finnish, a complete direct object takes what looks like the genitive –n ending but functions as the accusative. It shows you’re borrowing the entire book, not just part of it.
• kirja (nominative) = book
• kirjan (object with –n) = the whole book

Why is the relative pronoun jonka used here instead of joka?

Relative pronouns agree in case with their antecedent.
• joka is the nominative form (“which/that”).
• jonka is the genitive form, matching kirjan (which is in genitive/accusative).
Hence: kirjan, jonka … (“the book that has … of it”)

What case is jokaisella sivulla, and why is it used?

Jokaisella sivulla is the adessive case (–lla/–llä), used for “on something.”
• jokainen = “each/every”
• sivu = “page”
Adessive shows location “on every page.”

Why is sivulla also adessive, and not nominative?

Because you’re describing location (“on the page”), you need the adessive: sivulla. In Finnish, any noun indicating “on/at” a surface or place takes –lla/–llä.

Why is kaunis kuva singular rather than plural?

The sentence says there is one beautiful picture on each page. If there were multiple pictures per page, you’d use plural partitive:
• kauniita kuvia = “beautiful pictures”
But “one picture on each page” = singular nominative kaunis kuva.

Why is there a comma before jonka?

In Finnish, relative clauses—whether restrictive or not—are set off by commas. The comma signals the start of the clause describing kirjan.

Why is there no minä (“I”) before aion?

Finnish verb endings already encode person and number, so the pronoun minä is optional. The form aion clearly indicates 1st person singular, so you can omit “I.”