"I am not able to run but I am able to write."
Translation:Níl mé ábalta rith ach táim ábalta scríobh.
What "ní féidir liom..." version? If you got this sentence in a "Mark all correct" exercise, other people don't get the same sentences, and most people seeing your question will only have encountered this exercise as a regular translation exercise.
Ní féidir liom means "I can't" in the sense of "it's not possible for me to", rather than "I'm not physically capable", so it's not really the right choice for this exercise.
>>If you got this sentence in a "Mark all correct" exercise...
Yes, I did.
>>Ní féidir liom means "I can't" in the sense of "it's not possible for me to", rather than "I'm not physically capable", so it's not really the right choice for this exercise.
Well, a few lessons further on, I've just had a "Tap the word pairs" where "féidir” was paired with "able" —so, a bit inconsistent.
Yes, Irish and English are two different languages, and you can't simply do word for word substitutions in many cases. That's not inconsistency, it's simply a reflection of the fact that translation between languages is not an exact science (otherwise we would have had machine translation a long time ago).
In English, "I can't" and "I'm not able to" are often interchangeable, so "I can't help you right now" and "I'm not able to help you right now" could both be translated as Ní féidir liom cabhrú anois díreach, but "I can't run" usually means "I'm not physically capable of running", and Ní féidir liom rith doesn't have that meaning. If Duolingo was only teaching you one of is féidir le, in ann and ábalta then you could simplify the exercises down to always use that one version, but you would lose out on the different shades of meaning that are involved.
For example, Obama's 2008 slogan "Yes We Can" is translated as Is Féidir Linn. Even in English, you could say that "Yes We Can" means the same thing as "we are able to", but it's immediately clear that you can't just swap one for the other, and Is Féidir Linn is a much more effective translation of the translation than Táimid in ann or Táimid ábalta.
I don't understand your confusion. If you interpret "I can't write" as "I'm not capable of writing" (whether that's because your writing hand is in a cast, or because you never learned how to write), then Níl mé ábalta scríobh is a better translation.
The simplest interpretation of "I can't run but I can write" is best translated with Níl mé ábalta. But in other contexts, particularly aspirational ones, like "I can have ice-cream for dessert!", Is féidir liom is a more appropriate translation.
That was my thought. Nothing wrong with níl mé, but my first thought was "Where's the option to use nílim?" I imagine that Irish may not have the same need for stylistic matching that English does. In English I would choose either "I am not able to run, but I am able to write" or "I'm not able to run but I'm able to write." I would choose either the contracted form or the uncontracted, though a mix would not be "wrong". I'm guessing Irish has no problem stylistically with a mix of synthetic and analytic forms - in fact scilling (thanks, scilling) suggests as much elsewhere in these comments