You need to realise that there are two different "-ing" forms in English.
Gerund: this is a noun-like entity used in things like "I love swimming" or "Just watching is boring". It's often interchangeable with the infinitive form: "I love to swim", "To watch is boring". In Spanish it's usually translated with the infinitive: "Me encanta nadar", "Solo mirar es aburrido."
Present participle: this is an adjective-like entity used in things like "We ended up waiting", "She looks at me, smiling", or "the running child". It's usually used when something is in progress while another action is happening. In many cases it's expressed with the gerundio form in Spanish. (Yes, the name is confusing.) "Terminamos esperando", "Me mira sonriendo". The true-adjective form like in "the running child" is usually expressed with a relative clause, though: "el niño que corre"
This response (as well as your other one in this thread which further explains gerundio etc) have been a huuuge help in trying to understand this! Thankyou! It has been racking my brain every time it pops up in lessons, which is pretty often. Double checked with my native-Spanish-speaking friend in Spain and they say both posts are 100% correct
But in the exercise, y'all are asking me to translate -- and it's NOT "I like running," it's "I like to run." In conversation, I completely agree -- it doesn't matter. For the sake of getting the exercise correct, this program is actually teaching me to respond with an incorrect answer...
If we're having conversation, that's one thing. These are exercises, in which you're asking me very specifically "translate this:" ... The TRANSLATION (not the context or the idea) is "I LIKE TO RUN," not "I LIKE RUNNING" -- which would be (sort of) "A mi me gusta corriendo," and we don't say it like that in Spanish. The proper translation to the question given is "I like to run on the beach."
Corriendo is the gerundio form, which usually matches the English present participle. Both are adjective-like. "I am running" - "Estoy corriendo." Both words here describe a state.
But the "running" in "I like running" is not a present participle, it's a gerund, a noun-like form. It doesn't describe a state, but an activity. And the noun-like form in Spanish is indeed the infinitive:
- Me gusta bailar. - I like dancing.
- Leer es divertido. - Reading is fun.
- Mi deporte preferido es ver los deportes. - My favourite sport is watching sports.
You can, of course, replace the gerund with the infinitive, "I like to dance", "To read is fun", or "My favourite sport is to watch sports", but that won't change the Spanish translations - or the meaning.