Gustar is one of those verbs (encantar, importar, interesar, etc.) that end up turning the English sentence around. The sentence literally says "going to the beach is pleasing to my parents."
It might help to think of "a mis padres" as meaning "to my parents."
It's really an "a phrase" being used to provide information about the required indirect object pronoun "les."
Les gusta ir a la playa means they like to go to the beach (or you plural like). But that's not enough information. So you add my parents (in an "a phrase"), and leave in the les, which is still required but is now no longer translated.
My friends like music. A mis amigos les gusta la música.
My brother likes to study. A mi hermano le gusta estudiar.
Much more explanation, examples and quizzes at studyspanish.com (Grammar Unit Four).
Using the search term, I found this with the Google Search Engine:
Gustar is a member of a class of Spanish verbs sometimes called "backward verbs." Sentences that use these verbs have an abnormal sentence structure. Rather than appearing at the beginning of the sentence, the subject comes after the verb.
So, here is my more abbreviated, and hopefully, easier to understand update:
The colloquial translation of "A mis padres les gusta ir a la playa" is "My parents like to go to the beach." However, the literal translation of this Spanish sentence is "To my parents, to them, it is pleasing to go to the beach," and this translation has the syntactical order of the indirect object (IO) noun "A mis padres," the null subject pronoun "it" as the IO pronoun), the backward verb "gusta," and the direct object "noun substitute," and "ir a la playa" (to go to the beach). In English, "to go to the beach" is an infinitive phrase, and by definition, infinitives in both Spanish and English can function as noun substitutes.
Apologies to pat92981 and anyone else who wondered what on earth I was trying to say. I came back to this comment two years later, and also found it confusing and incorrect. Apparently, five others agreed with you!
So, I got rid of the confusing and incorrect parts and updated the comment with the benefit of two years of additional study on my part.
Not sure I understand. I see that one can correctly say, "A mis padres les gusta ir a la playa." Is is incorrect to say, "A mis padres les gustan ir a la playa."? If so, why? It seems like all of a sudden we have stopped conjugating, "gustar", and I don't understand what is the point of doing so. What am I missing?
Yes, "A mis padres les gusta
n ir a la playa is wrong, because "gustar" must be conjugated according to the subject "ir". With "gustar", the thing being liked in the English version is the subject in the Spanish version. Think of it this way: a little bit more literal translation of this Spanish sentence into English is--
Going to the beach please
s my parents". We have here "Going to the beach" as our sentence subject. We conjugated the verb "please
S" to match "Going to the beach", right? That's kinda what happened to gusta and why it cannot be gusta
N: because the subject "Ir a la playa" is not plural.
• A mis padres les
el libro «To Kill a Mockingbird»
= "My parents like the book 'To Kill a Mockingbird'" (regular translation)
The book 'To Kill a Mockingbird' please
s my parents." (a bit more literal translation)
• A mis padres les gusta
= "My parents like books." (regular translation)
please my parents." (a bit more literal translation)
When a verb like "gustar" has an infinitive (or an infinitive phrase) as its subject, then the infinitive/infinitive phrase is a "noun substitute" that is always singular in number. For example "Les gusta ir a la playa" (To go to the beach pleases them). Also, Spanish infinitive subjects can be translated as either English gerunds or English infinitives, given that both are considered to be "noun substitutes."
"parents" is the indirect object in this Spanish sentence. The subject of "A mis padres les gusta ir a la playa" is the infinitive phrase "ir a la playa" (to go to the beach). " "Ir a la playa" can also be translated as "going to the beach" because English infinitives and gerunds can both be "noun substitutes."
The female voice pronounces "ir" like "isssz" with no English "r" sound at all. Is this how it is pronounced in Spain? Is it idiosyncratic by country? I ask because I'm fairly sure Duo's program often gets pronunciation because they make mistakes in French -- and I used to work for a French company, have been to France many times, etc. And the mistakes are simply bizarre.
With verbs like gustar and encantar (or others like them), the les (or other indirect-object pronouns: me, te, le, les, nos) is grammatically required. The "a mis padres" is grammatically optional and is only there to clarify (or emphasize when you need to do so) who les is (because les can be standing in for "they"/a ellos, "you"-plural/a ustedes, "my neighbors"/a mis vecinos, "your friends"/a tus amigos, etc.)
If the indirect object of "gustar" is a noun, then that noun must be introduced with the preposition "a." For example, the sentence "A Maria le gusta David" (David likes Maria) has "Maria" as the optional indirect object noun, "le" as the mandatory indirect object pronoun, "gusta" as the verb, and "David" as the sentence's subject.
Because of the structure of this how this is said in Spanish. The word "gustar" doesn't mean "like" as we would say in English. There isn't a direct translation for that word.
The word "gustar" means "to please".
The literal English translation of "A mis padres les gusta ir a la playa" would roughly be "To my parents it pleases them to go to the beach".
In this case "gusta" means "it pleases". If you were to use "gustan" that would translate into "they please", which would just not make any sense in this sentence.
That translation would look like "To my parents they please them to go to the beach".
So whenever I come across the word "like" in an English translation, I always try to reformat the English sentence into "it/he/she/they please(s)" before translating the sentence into Spanish. It really helps to eliminate the confusion.