All utterances in Finnish have a falling intonation. In English, however, yes/no questions have final rises, which are not perceived as natural in Finnish. Finnish listeners would rather expect a question particle, -ko/kö and a falling tone. I am so proud when my relatives congratulate me by telling me that my questions sound normal and non-pretentious even after 40 years in the US: So be careful when a Finn asks you a simple question. You may not want to show that you did not understand. So you just smile, nod and appear attentive. But do not be surprised if a Finn after repeating the question a few times will get angry and switch to English.
Generally the question word begins the sentence but retains the SV word order otherwise. So if we want to turn 'Tämä kirja on Lean' (this book is Lea's) into a question we retain 'tämä kirja on' as a basic SV word order and just put 'kenen' (whose) at the front. Kenen tämä kirja on? Whose book is this? So you just keep the word order of a statement and place the word which asks a question in the beginning? That seems easy enough, right. Kysymyssana
Every sentence can also be transformed into a yes or no question by using -ko-particle normally at the beginning of the sentence.
Päivi rakastaa Hannua. --> Rakastaako Päivi Hannua?
Tämä kirja on Lean.--> Onko tämä kirja Lean?
You can inquire after about any element, not just the verb. in your sentence by adding the -ko particle to it. You can put the words in almost any order (it's the -ko-particle which tells this is a question, not the word order like in English) but normally you start with the word which has the -ko-particle.
Päivikö rakastaa Hannua? Oh, it is Päivi and nobody else who loves Hannu.
Leanko tämä kirja on? Just wanting to confirm that this book is Lea's and nobody else's.
Syyskuussako koulu alkaa? I am just wondering if the school begins in September and not in August.
Onks sulla...?
Conditional