I was speaking to a Spanish native on Speaky and she used the following sentences

Es loco lo sé. It's crazy I know.

Eso lo supe en la universidad. I knew that at University.

This use is confusing to me because if I was translating these English sentences to Spanish I would have omitted lo in both cases.

  • the indicative "lo" and "le" are different from one another, while lo works in the direct object, le works with the indirect object
    – Mike
    Commented Mar 28, 2018 at 15:39
  • @walen - Good find, and I agree. Commented Mar 29, 2018 at 2:45
  • @walen I disagree again, the OP knows what lo is, they just doesn't understand why it's being used with saber (because in English the DO wouldn't get used). Commented Mar 29, 2018 at 13:04
  • @guifa I agree with you, this question is more basic than the previous ones, maybe the word is the same, but the reason behind the use is different, and for the usage of "lo". i would like to see similar questions with different explanations for the community as both direct and indirect objects are complex to explain
    – Mike
    Commented Mar 30, 2018 at 17:45

3 Answers 3


Different things are happening there. Your first example is actually not correct in Spanish as written, as it's not, I think, in English; there should be a comma in there, because there are two propositions:

Es loco, lo sé. = "It's crazy, I know."

The Spanish equivalent of "(...), I know" is not the literal translation. Lo sé properly means "I know it", where "it" refers to the fact that you've stated just before that. You can also add ya and either leave the pronoun or drop it (ya lo sé or ya sé = "I already know"). You cannot under any circumstances say just "I know" in a phrase like that.

On to the second sentence:

Eso lo supe en la Universidad. = "That I knew at University."

There you have a different case. Following the usual word order in Spanish (subject - verb - object) you would say (Yo) supe eso en la Universidad. Note there's no pronoun lo there. But that's not what you're saying here. You're moving the direct object (eso) to the front in order to make it the topic of the sentence. When that happens in a sentence like this, it's as if you have left the direct object slot empty, and since it has to be filled, we use the pronoun (in this case, lo). In way what you're saying is equivalent to

En cuanto a eso, lo supe en la Universidad. = "As for that, I knew it at University."

Some examples of this latter kind:

  • El árbol lo talaron ayer. = "The tree, they felled it yesterday."
  • La nueva mesa me la enviarán mañana. = "The new table, they will send it to me tomorrow."
  • A los perros los vacunamos cuando cumplen un mes. = "The dogs, we vaccine them when they turn one month old."
  • Tu asunto lo veré más tarde. = "Your thing, I'll see about it later."

The pronoun is compulsory in all these cases. In English you can say things like "The table they will send tomorrow" or "Your problem I'll attend to later", but not in Spanish. Note also how in English these ideas would be more commonly conveyed using the passive voice ("The tree was felled yesterday"), which in fact achieves the same thing (turning the object into a subject and moving it to the front, which makes it the topic). The passive voice is not nearly as common in Spanish, least of all spoken Spanish.

  • partially because the first sentence was not correctly written in english as well, "It's crazy I know" should be written " it's crazy i know THAT/IT , creating a indication, and thus indicating we need to use the "direct indicative "lo/la"
    – Mike
    Commented Mar 28, 2018 at 15:43
  • 1
    @Erin "It's crazy, I know" is perfectly fine English. Although "It's crazy, I know that" is grammatical English, it does not fit the context (it would work if the context were something like "It's crazy, I know that, but I don't know this easy thing), ditto for "It's crazy, I know it" which would virtually always be interpreted as "it's crazy [that] I know it [=some fact]" comma or not. Commented Mar 28, 2018 at 15:53
  • @guifa, then you have to translate it as "es loco, yo se" instead of "es loco, lo se", without the indicative the translation is different, also, it's crazy that i know it translates as "es loco que lo sepa"
    – Mike
    Commented Mar 28, 2018 at 15:56
  • 2
    @Erin One can translate words or one can translate meaning. They don't always give the same result. I've never heard a Spanish-speaker say "es ___, yo sé", they always say "es ___, lo sé" for what an English-speaker would express as "It's ___, I know". For what the English-speaker means with "It's ___, I know that", the Spanish speaker would employ a demonstrative likely along with the direct object as well (depending on if it's being contrastive): "Es ____, eso [lo] sé". Commented Mar 28, 2018 at 16:02
  • 2
    @aparente001 I'll try and do that. The explanation about word order has to do with why the pronoun must be present in the example, where it would not if the order was the more usual one.
    – pablodf76
    Commented Mar 28, 2018 at 21:50

In online communication, people often omit punctuation. The first sentence is actually

Es loco, lo sé. It's crazy, I know. OR It's crazy; I realize that.

For the second sentence, I'll give an alternate, freer translation that will hopefully help to convey the idea:

Eso lo supe en la universidad. I came to know that at University.

You would like to know why "lo" is being included, since when you tried to go from the English idea to a Spanish sentence, you didn't include "lo."

The answer is that it is idiomatic to include "lo" in sentences such as these.

Note that object pronouns typically go before the verb in Spanish, for example

  • Yo tengo tu libro --> Yo lo tengo.

  • Yo sé que tú tienes mi libro --> Yo sé que tú lo tienes.


When "it" or "that" are used as indicatives of the subject they are replaced by Lo/La .

And interesting case is the "le" that is used when the indication refeers to someone else.

You can research more about this with the Direct object and Indirect object, and to understand this i would recommend to read in Spanish rather to trying to translate from english.

Also for this specific case maybe "Dora" is a good example , with her signature Phrase "We did it/lo Hicimos"

  • My Spanish is no where near as good to start reading about Spanish grammar unfortunately. Hopefully it will be soon. :) Commented Mar 28, 2018 at 18:31
  • @Spanishbeginner - I'm not sure where you live, but many public libraries and elementary school libraries have children's books in Spanish. If you go to browse, try to choose books that were originally written in Spanish, since some of the translated books are not the best translations in the world. Commented Mar 28, 2018 at 19:11
  • also in this specific case maybe "Dora" is a good example , with her signature Phrase "We did it/ lo Hicimos"..
    – Mike
    Commented Mar 28, 2018 at 21:41
  • @Erin - Do you want to add that to your answer? They say comments are ephemeral.... I just realized today that you changed your username, you used to be "Mike," right? Should I say welcome back? I was wondering recently what had happened to you. Commented Mar 29, 2018 at 1:12
  • Yup, I'm back, i was doing experiments with my other stack exchange accounts and after switching one account it switched them all and i've been to lazy to switch my name back
    – Mike
    Commented Mar 29, 2018 at 14:53

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