does senare share a common ancestry with sayonara or is that just a gigantic coincidence. I mean, they come from completely different languages from completely different parts of the world, but they feel so similar to me
I think they are not related at all, but that's how I memorized this word.
The difference is very small. If you say ska, you express a little more determination or intention: you have decided to call. But the difference is small.
It's probably more common to say just ringer here in Swedish, but both ways are fine. You can also use our other future construction and say Jag kommer att ringa dig, but we haven't taught the future tenses yet at this point.
Whats wrong with 'I ring you later', I know it doesn't sound very natural in English, but semantically why isn't it correct?
I've added that option as an accepted answer too. Obviously the present tense doesn't sound good here in English (while it's perfectly natural in Swedish) but using ring instead of call or phone doesn't make it any worse.
I shall ring you later could be translated as Jag skall ringa dig senare
So with you saying that present tense is natural in Swedish, does that also mean something like 'Jag får ett arbete' is also natural, compared with 'Jag fick ett arbete'?
fick is past tense so I'm not sure why you'd want to compare those two. A sentence like Jag får ett arbete would most likely be interpreted just as present tense/something general since there's no reason to think it should be future. In the sentence above, there's senare which shows it's in the future. Also, får is not something you can really decide for yourself (more so in Swedish than in English: not every English get should be translated into Swedish får). Normally we only use verbs that include a component of intention as the present-for-future, and får does not include any intention.
It is one of the ways. You learn about the other ways a little later in the course. So, you can:
- use ska
- use kommer att
- use a verb in present tense paired with a word that signifies a future time eg Jag reser till kina imorgon. (As the sentence above does.)