This literal translation thing is pretty annoying. The correct English translation to me would be "I WILL go, if you go too" so why isn't it accepted? I suppose the average duolingo user can understand that "ik ga" is present tense, even though it translates to "I will go" in this case.
You misunderstood his post. His point is that Duolingo tends to ask and expect only literal translations as correct, no matter how awkward the translation is in English. "I go if you go too" is something nobody would say. You would say "I go if you do" or "I go if you go", but in this case neither of those are accepted.
An issue we all face is international English - i.e. an English spoken by millions of people whose native language is not English. We get very used to hearing people say "I go if you go too" and we understand it, but it is not natural.
The second issue is context. For most phrases in Duolingo, there is a translation that immediately jumps out at you as being the most natural: however in certain contexts, that translation would be wrong and another would fit better.
For this sentence, the two that come to my mind as the ones I would say are "I'll go if you go (too)" or "I'm going if you are (too)". It is almost impossible to think of a context where "I go if you go too" would work.
I'm not sure I get what you were trying to say.
As far as I know, indien and als (when als is used as a subordinating conjunction) are synonyms, the difference being that indien is more formal. Any thoughts from native speakers?
You can find more information about this here: https://onzetaal.nl/taaladvies/als-wanneer-indien
And here: https://www.taaltelefoon.be/als-indien
Sorry but all the information I found is in Dutch.
In my French-Dutch dictionary: "si" which means "if" was usually translated as "als".
"indien" was replaced with "à condition de" which is "on the condition of" which can also be replaced with "if", but you can see that it has a different flavor. I agree with AZ-Dude that it is closer to "but only if". .I would say "only if".
The example in the dictionary is "To pay a less expensive entry fee on condition of being at least 65 years old." http://dictionnaire.reverso.net/neerlandais-francais/indien
"mits" was replaced with "à condition que" which is "on the condition that" which again is very similar. I can see why you asked and I hope a Dutch expert gets back to us soon. In the following example it is used in "We'll buy the house on the condition that we can move in next month." http://dictionnaire.reverso.net/neerlandais-francais/mits/forced
This is what I found:
Indien= in case
Mits= provided that So the latter seems to be more 'forceful' or something.
In you first sentence, the condition the speaker is setting is that 'I' go, the consequence of the condition is that 'you' go (your 'going' depends on that 'I' go).
If I go, you go= you'll go (only) if I go.
In the original sentence, the condition the speaker is setting is that 'you' go, so that 'I' go.
If you go, I'll go= I'll go (only) if you go.
Sorry, but I cannot explain it any better, you're just inverting what is the condition and what it is that depends on that condition taking place.