I saw this phrase in a Rosetta Stone lesson "Hiciste lo suficiente como para aprobar el examen" I know the translation is "You did enough to pass the exam" but why is "lo" before "suficiente?" It seems unnecessary, but I've seen "lo" preceding other adjectives like this before, and I can't understand the grammatical reason behind it. Thanks!
Use of "lo" before an adjective
'lo' is referring to 'the thing' that was done in order to pass the exam. Without 'lo', it would be something like 'You did sufficient to pass the exam', but with 'lo' it's kind of like 'what you did was enough to pass the exam' or almost literally 'you did the sufficient thing to pass the exam'
I see qfreed has given a much better answer....
I would add that 'lo' in this context is also gender neutral....
Lo is Spanish's neuter definite article. It is used with abstract concepts or unknown nouns where the gender is indeterminate.
Adjectives modifying a noun match the gender and number of that noun.
In your examples, the adjective is being used as a noun. Adjectives used as a noun aren't modifying another noun so they have no gender. Therefore, the neuter definite object is used with them rather than el or la.
lo suficiente (adjective as a noun) la razón suficiente (adjective modifying a noun)
Now as to why any definite article (whether lo/el or la) is used in before the adjective used as a noun, is a different rule. Definite articles are used with abstract nouns or nouns that represent a general classification. la justicia la verdad el valor, etc.
Not that I am trying to start an argument, but Jack's answer and mine are diametrically opposed (and his viewpoint is the one that I previously subscribed to). However, in view of the article that I quoted I have had to alter my previous viewpoint. Could someone familiar with the grammar involved clear up the discrepancy. Jack's version is that the "lo" is the noun (the thing) and that the adjective is still an adjective modifying the noun "lo". The quoted article's viewpoint is that the adjective is being used as a noun and that the "lo" is the definite article (subset of adjectives). As you can see these viewpoint are in direct contrast with each other. Could someone clarify the grammar? I've been hoping someone would arbitrate, but no more replies have been made.
I may be wrong, and I welcome someone to jump in and clarify, but the only way this makes sense to me is to consider the "lo" as the neuter article, and in this usage (combined with the adjective), "lo suficiente" becomes the noun, which would be translated "the sufficient thing" (in this context). From one of my textbooks, lo + adjective" is typically translated to English as "the + adjective + one" or "the + adjective + thing." So "lo suficiente" is "the sufficient thing."
In my humble opinion