grammar.pronouns.direct-object
Direct object pronouns: me, te, lo, la, nos, os, los, las
Lo/la/los/las replace the direct object and go before the conjugated verb: lo veo, la compré.
grammarA2v0.1.0
Explication
Me, te, lo, la, nos, os, los, las. They precede conjugated verbs (lo conozco), but attach to infinitives, gerunds, and affirmative commands: quiero verlo, estoy leyéndolo, cómpralo.
Lo also stands for whole ideas: lo sé ('I know [that]'). In Spain, le for a male person (le vi) is accepted leísmo; Latin American standard keeps lo.
Exemples
¿Las llaves? Las tengo yo.
The keys? I have them.
The keys? I have them.
Région: global
No lo sabía.
I didn't know (it).
I didn't know (it).
Région: global