BTW, I just realized this. He adds up (sums) is very different from "add the apples to something.)
For this other version of "add" (to add something to), apparently the appropriate verbs are "anadir", "agregar," (to aggregate) and "incorporar" (to incorporate)
Sumar is the adding up to a total. It can either be numerically additive or metaphorical.
- Cuatro y uno
sumancinco - Four and one
Añadir is just adding, and is less concerned about the whole, and is more about the action.
- Basta con
añadiruna cucharadita de la pasta de Ají Amarillo y disfrutarás del sutil sabor picante de esta receta - Just
adda teaspoon of Yellow Pepper paste and enjoy the subtle spicy flavor this recipe (Ahora quiero papas huancayo. !!!Que rico!!!)
But they overlap in meaning, especially when being used to describe a metaphorical addition
Solo hay dos cuestiones que quisiera
añadira modo de breve nota - There are only two questions that I would
addin the form of a brief note
sumarmi voz a las condenas de otros - I would
addmy voice to the condemnations of others
Even then the implication with sumar is that you are adding to the total. So which word you choose is a question of what you wish to express, adding to a total or just adding.
I used 'He adds up the apples' and it was accepted. Another question from a non-native speaker, would 'He sums up the apples' be a correct translation?
You are right that was not clear. "He sum the apples." does not work, because there is no verb. If you were thinking, "el" instead of "él", that doesn't work because the noun is feminine "la suma". "To sum up" is a verb that does not mean add, but "to summarize". Yes, the verb is not just "sum" the preposition "up" is a required part for it, so "sum" by itself is a noun. http://dictionary.reverso.net/english-spanish/sum/forced
You could also be talking about a recipe in which you have to add the apples to the water to boil them. I do hope we are adding sugar next!
X amount of water
Y amount of apples
.Z amount of .......
- Put water in pot.
- Add apples
- Add sugar ?!!!
So it is perfectly okay to say "He adds the apples." in English. We will assume he is adding them to something previously mentioned.
In Central America, I had been taught that a measurement of land (something like an acre) was a manzana. (Really confused me cuz I thought they were talking about apples!) So I said that he was counting "blocks", like in the hint, and that was wrong. I'm not concerned about Duo marking it wrong, just wondering if I'm totally confused or not?
Where did you get any indication that this should be sumar? The English sentence say "he adds..." and the Spanish uses añadir. There's no math involved here. He could be baking or pitching in with food.
(EDIT) Another thought. Did you get an alternative sentence with sumar? If so, he can add apples mathematically. It doesn't need to be "add up" to make sense.
The indication that this is sumar: "Él suma las manzanas." I copied it from the top of this page. Now, do I support having sentences that are grammatically correct but with "stretched" vocabulary? Certainly, as a teaching strategy, I think it has value. I'm not learning a phrasebook, but rather a language. I may never use this sentence in conversation, but both sumar and añadir are indelibly in my vocabulary, together with how to use which one and when.