"Czy ten fotel jest dosyć miękki?" - why not?
Yes, definitly a good option, dosyć miękki or dość miękki - it's the same.
But, unfortunately, my option wasn't accepted.
Okay, "dość" and "dosyć" added.
Just please remember that both 'dość' and 'dosyć' may also mean 'quite', so 'dosyć miękki', especially in a declarative sentence, can be understood as 'quite soft'.
Why is "Czy ten fotel jest dostatecznie miękki?" not accepted? It is correct!
Oversight, added.
Oh man! For an English speaker, this seems almost impossibly contorted. My wife says, the more Polish I learn, the worse my English is becoming. ;)
Lol. Same here. My English and my German are becoming worse too. :D
Is that the cost we have to pay? Ha, ha.