you are right there are more complicated sentences which don't have the structure of subject, one verb and object. However the main rule in German sentence structure is that the verb should always be the 2nd "idea" in a sentence.
Here is a typical sentence of subject (S) followed by the verb (V) with the object (O) at the end.
Deine Mutter (S) backt (V) Kuchen (O) – Your mum bakes cake. Don't let yourself be irritated by adjectives.
Deine liebe Mutter (S) backt (V) einen leckeren Kuchen (O).
When the sentence goes into a tense, the part of haben, sein or werden comes after the subject and the relevant form of the main verb goes to the end.
Deine Mutter (S) hat (V) Kuchen gebackt – Your mum has baked cake.
Sentences with a subject, one verb, an indirect object and direct object
Deine Mutter (S) backte (V) der Frau (IO) den Kuchen (DO) Your mum baked the woman the cake.
Deine Mutter (S) backte (V) den Kuchen (DO) für die Frau (IO). Your mum baked the cake for the woman.
Adverbs are in general placed next to the words they are referring too but if you place them at the start you get the same structure you would use in a question. The reason for this is as I mentioned before, the verb has to be placed 2nd in a sentence.
Normalerweise backt Mutter Kuchen. - Normally mum bakes cake.
Backt Mutter Kuchen? - Is mum baking cake?
I hope it helps!
P.S.: I corrected your sentences in the forum section 'German conversation'.