I have been listening to にじいろ／絢香 and started to translate some of the lyrics but I got stuck with this part: ずっと長く道は続くよ。 The whole sentence is like this:
これからはじまるあなたの物語
ずっと長く道は続くよ
にじいろの雨降り注げば
空は高鳴る
My question is: What is the purpose of the は here? What I know about は is that we use it to introduce the topic. So if the 長く道 here is the topic, and 続く is the verb, what exactly did it do to the topic since we use は instead of を which I learned that we use with verbs.
続く is an intransitive verb. It doesn't take an object and so doesn't take the particle を. This verb is used when something continues without an explicit agent i.e
いい天気はつづく
The good weather continues
Nobody continued it. It just continued on its own.
The equivalent transitive verb is 続ける. This is used when somebody is actively continuing something and requires an object marked by を:
話を続ける
I continue my story.
Japanese has many of these transitive/intransitive verb pairings.
So in your example, the road (the topic) continues. If you used 道を続ける that wouldn't make much sense. Not sure about Japanese but if you 'continued the road' in English that would imply that you were still building it.
Because 続ける is intransitive your other choice would not be を but rather が、as in 長く道が続く.
I'm not native so I'd love to know if that is unnatural or not. My intuition is that は is much more natural than が, because:
が puts too much attention on the subject ("the road is the thing that will continue") which is unnatural
道 is basically the same thing as これから始まるあなたの物語 which has already been talked about (and is a universal thing like the sun or the sky), so using は is the normal choice
