All ok. All similar meaning. (1) While he was eating, I asked him to lend me twenty pounds. == He will want the money back one day. (2) While he was eating, I asked him for twenty pounds. == No idea of the terms/arrangement (3) While he was eating, I wanted him to lend me twenty pounds. == You thought it. You may or may not have told him. (4) While he was eating, I asked for twenty pounds from him = = No idea of the terms/arrangement (2) & (4) are basically equivalent.