"Atender" is translated as to assist in Spanish, while "asistir" is translated as "to attend". These words seem to be cognates of each other, but have opposite meanings when translated. How did this occur? Are there any research articles/ journal papers describing how one deviated from the other?
Los orígenes de ambas lenguas no se basan en las mismas raíces. El inglés tiene sus raíces en lenguas germánicas, pero en algunos casos la raíz viene de palabras francesas, como es el caso de 'attend' y 'assist'.
En español, 'atender' y 'asistir' provienen directamente de las raíces latinas:
- Asistir: 'assistere' formada por el prefijo 'ad' de proximidad y el verbo 'sistere' (tomar posiciones, estar en un sitio fijo).
- Atender: 'attendere' formada por el prefijo 'ad' de proximidad y el verbo 'tendere' (tender o estirar), que aunque no es el significado de la palabra en uso común, se utiliza para hacer referencia a las acciones de ayudar o estar concentrado en alguna acción.
Por contra, las palabras inglesas 'attend' y 'assist' vienen del francés 'atendre' y 'assister'.
Aún así las palabras 'attendre' y 'assister' tienen las mismas raíces que sus respectivas en español. La diferencia entre el significado tanto en español como en francés respecto al inglés se debe a las influencias germánicas, y no a las latinas, dado que en francés el significado de estas palabras es el contrario que en inglés pero igual que en español.
According to sources like this, the English versions of the two words are derived directly from the Latin. So it then becomes a question of how they deviated in Spanish.
"Assist" has something of the connotation of "seat" (la silla) in Spanish. That could lead to the meaning of "to sit in" or participate in, i.e., "to attend."
"Attend" has something of the connotation of "to wait." Originally it meant to "wait FOR," but the meaning in Spanish somehow turned to "to wait ON," which could mean "to assist" or "to help."
The accepted answer is dubious. There is no evidence that any Germanic influence is involved in the difference observed between these verbs given the fact that at the time English borrowed these words from French, they already had multiple meanings.
In French, assister means to attend when transitive direct (J'assisterai au concours de danse = I will attend the danse competition) and to assist when transitive indirect (Je les assisterai pour le concours = I will assist them for the competition). The single substantive assistance means either the audience or the help/aid. This duality can also be found in English, Spanish and Italian (assistere means both to assist and to attend)
The modern French attendre means "to wait" but also had, during the time French was spoken by English aristocracy, the different meaning of "being attentive", "pay attention to" which was the one kept in English.
Attendre, atender and "to attend" all eventually come from the Latin adtendere (to extend1 toward) while assister, asistir and to assist all come from the Latin adsistere (to stay toward, close).
Looking back to the roots, it is clear there is a logical link between all of these forms. They are not opposite but happens to have their main meaning more or less specialized.
It can be noted that the current French attendre currently mean "to wait" which commonly translates to esperar in Spanish. In French, espérer does exist but is now specialized to mean "to hope".
It is just a natural tendency for words to diverge over time, and meanings either to narrow or to widen when two branches of a common ancestor grow on their own.
1 To "extend his mind toward" in that case.
Both assist and attend (English) come from Latin through French (Old French, Middle French) into English. English is a Germanic language, but English words are not necessarily derived from German or any Germanic language. The Norman conquest of Britain in 1066 and subsequent centuries of Norman French introduced many word items into English (along with syntax and morphology).
The Germanic and Celtic languages and Latin (Vulgar Latin) had centuries of contact (speaking in terms of speakers in contact), and it is sometimes not immediately clear that "Germanic" or Celtic word items in Spanish are Germanic or Celtic, respectively, because they came into Spanish (Romance, Old Spanish) through the period of Roman occupation and bore Latin inflections. Germanic and Arabic contact produces toponyms in Spanish as well. If you want to visualize Roman-Peninsular contact, it is portrayed in The Gladiator, a a film set in Spain's Roman period, whose the protagonist is known as "The Spaniard."
I'm spanish and I would say that 'asistir' is like when you're going to an event, a class, etc, so, you're present there, you went to the event.
By the other hand 'Atender' is said when you're waiting for something in a formal way, but, it's commonly used to say that you're taking atention on something, like listening your teacher, etc.