Gerunds vs. Participles in Spanish

[satchrocks]

As far as I can tell, the equivalent of adding the letters "-ing" onto a verb (running, flying, etc) in English is achieved in Spanish is by adding "ndo" to the infinitive - esperando, mirando, etc.

Is this acting as the participle (adjective form) or gerund (noun form) of the verb (or both)?

For example, which is correct:

Dormiendo es mi actividad favorita.
Sleeping is my favorite activity.

OR

La muchacha esta dormiendo ahora.
The girl is sleeping now.

Thanks in advance!

[CrOtALiTo]

I want to give you a hint about your questions.

In my own opinion the first one is the more near to your answer.

But although I'm Mexican and the Spanish is my first language, I'm not sure in the answer, then I'm going to leave that other person answer the question.

[Rusty]

Don't confuse the Spanish word gerundio with the English word gerund. They are not the same.
The English gerund is a verb functioning as a noun. The Spanish equivalent is the infinitive.

Me gusta hablar español. = I like speaking Spanish.
Correr es bueno para la salud. = Running is good for your health.
Ver es creer. = Seeing is believing.
No fumar. = No smoking.

What you wrote about above is called the gerundio in Spanish. This is a verb form. In English, the equivalent is the present participle. The gerundio is used in the progressive tenses, as an adverb and to express continuous action.
The gerundio endings depend on the infinitive's ending:
-AR; use -ando
-ER and -IR; use -iendo

So, in your first English sentence, sleeping is a noun. Therefore, a Spanish infinitive will appear in the correct translation:
Dormir es mi actividad favorita.

In your second sentence, you chose to use the present progressive tense. Its construct is estar + gerundio. The verb estar is conjugated. The gerundio is fixed. There are some irregular verbs in Spanish, and dormir happens to be one of them. The gerundio of dormir is durmiendo. And, since an action in progress is always indicated when a progressive tense is used, there's never a need to say ahora.
Here is the corrected second sentence:
La muchacha está durmiendo.

[brute]

The confusion between English Gerund, an "ing" verb form used as a noun, and a Spanish Gerundivo, a progressive continuous verb form used with estar, is further confused by the use of the English Gerundive used to describe a Latin verb form. Is this the same as the Spanish gerundio?
It seems to me that they are all essentially present participles used as different parts of speech.

[satchrocks]

Originally Posted by brute

The confusion between English Gerund, an "ing" verb form used as a noun, and a Spanish Gerundivo, a progressive continuous verb form used with estar, is further confused by the use of the English Gerundive used to describe a Latin verb form. Is this the same as the Spanish gerundio?
It seems to me that they are all essentially present participles used as different parts of speech.

That's how they struck me when I first looked at them, and, in reality, the gerund/gerundive are pretty much identical between English and Latin; servandi means "guarding" or "saving" in Latin and can therefore be viewed as tantamount to the noun form of "to guard" or "to save" in English. Therefore, it is essentially just a future passive particible.

However, the Latin gerundive form (ending in the genetive -andi or endi and being declined normally from there) can only be used when the gerund is NOT the subject or direct object of the main verb, in which case the word is expressed in the infinitive (much like Spanish, apparently) - ergo, it does not have a nominative (subjective) case in Latin (as I just said, if it is acting as the subject, it takes the infinitive, much like it does in Spanish).

Further confusing things is that there is a "gerund" form of the verb in Latin (yes, slightly different than the gerundive construction), which I believe is used on intransitive verbs.

Many thanks to Rusty for clearing me up on my use of the word "gerund;" because I have only really studied English and Latin, I thought that the word "gerund" had a universal meaning that was interchangeable across languages; apparently, in Spanish, it is not interchangeable.

I'll take using the infinitive any day of the week!

[brute]

Its a confusing (adjective) idea. My understanding (noun) is being (verb) seriously challenged. Is my bank really guarding my savings? I do hope so!

[irmamar]

Spanish comes from Latin, so they have a lot of common points. It's been a long time I don't study Latin and I've forgotten almost everything, but in both languages, infinitive can be the subject, but the gerund never can be it. For instance:

Dormire necesse est.
Dormir es necesario.

You can see the contact points (I like comparative grammar )