Re: Faltar// MAR is correct-
Yoma-
You are the only one thus far who has demonstrated that grammar the science behind the language is key to decoding any phrase where the meaning is in question or ambiguous. However, your suggestion of [lo] instead of [le] is incorrect. Have you ever heard [lo] used with the verb faltar? I have not. Instinctively the pronoun I would use is [le] as would anyone else. The reason why is because faltar is an intransitive verb. This means it takes an indirect pronoun [le] and not a direct object pronoun [lo] or [la].
Faltar has many meanings in Spanish and is usually used in the third person. In grammar textbooks this verb is always broken down as 'faltarle algo a alguien (o algo)' in order for the reader to understand how to use the verb correctly.
Faltar can mean:
1/ no estar= Ej. Falta dinero
2/ no haber suficiente= le va a faltar dinero
3/ hacer falta= le hace falta alguien que le ayude
-these are just some basic examples I thought of to show how it is used in the third person to express everyday concepts.
Le faltó without expanding the phrase is difficult to understand out of context but if you break it down it's possible to understand. For example if I say:
1/ A Juan le falta dinero= Le falta dinero
2/ Al libro le faltan cinco páginas = Le faltan cinco páginas
By applying the grammatical rule above 'faltarle algo a alguien (o algo)' the meaning and format of the phrase is easily understood.
1/ Qué le falta= dinero
A quién= Juan (Juan can also be replaced by [le])
2/ Qué le falta= cinco páginas
A qué= al libro (which can be replaced by [le])
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Regarding the phrase in question [le] as an indirect pronoun can mean it, him or her.
Le faltó= "It was missing" as stated by M.A.R.
- it was missing (as in "it was missing in my account", tu westen union xxx). Refer to example #2.
Le in this phrase may throw people off because it's not stated what it refers to as I did in my examples above. However, the phrase of the original speaker falls completely within the grammatical parameters of the language.
-LDG.