gratis vs gratuito

Question

What's the difference between these two? I thought they were interchangeable but the exercise 'Campsite activities' doesn't accept 'gratis'.And, is 'canotaje' not used in Spain?Saludos

Answer

Hola Graeme,
Gratis and gratuito/-a/-os/-as are interchangeable when they are adjectives (which is what they are in this sentence in the exercise) Gratuito may sound just slightly more formal.
When it is an adverb, then we use gratis (or gratuitamente):

Han ofrecido todos sus servicios gratis (how? "for free": adverb)
Han ofrecido todos sus servicios gratuitamente (how? "for free": adverb)

I hope this clarified it.
I just added your sentence using "gratis" as also correct in the exercise.
Note: "canotaje" is not a Spanish word as far as I know. Did you get the right spelling? What were you referring to?
Saludos
Inma

Answer

Thanks for your answer Inma.Regarding 'canotaje', I first came across this word for canoeing on a site I was learning from that leans heavily towards Latin American Spanish . They did also accept piragüismo, but as a second preferred answer. Canotaje stuck with me because I couldn't work out how to type that ü at the time jajaja!Well, I just found it here https://www.spanishdict.com/translate/canotaje (a US-based site so often prefers Latin American Spanish variations). But oddly, it's not in RAE is it! This may sound strange but caBotaje is in RAE and kind of suggests 'navigation', so I wonder if it could it be a word that has been changed slightly in South America, to mean the Olympic sport 'slalom' perhaps? (https://www.ecured.cu/Canotaje). I'll leave that to the etymologists!Saludos :)