Yo y tú (or yo y él) vamos; tú y él vais.
A conjunctive pronoun should precede the verb in the Indic. Cond. and Subj. moods, but with the verb in the Indic. or Cond. mood a great latitude is allowed for the sake of euphony or emphasis. The principal idea is to give thereby more prominence to the verb, as—
Entreguéle los bultos, acordéle toda facilidad para el pago y quise acabarlo todo amistosamente.
The conjunctive pronouns lo, le, are both used for "him," "it" (m.), (direct object); the second is more generally used for a person, but no distinction is strictly observed.
Lo (not le) should however be used for "it," referring to a whole statement.
Lo translates often the English "so," as—
Lo digo: I say it, I say so.
Ya lo creo: I should think so.
The conjunctive dative (indirect object) should be le for both genders (sing.). La instead of le for the feminine is however permissible and is used by the best writers.
Les instead of los is often found in the accusative (direct object), masculine plural, but this should not be imitated.