"large cask (sounds like ton)"
This is an interesting one, because it raises a problem only in speech. In writing, the modern spelling distinguishes tun from ton (to which it is etymologically related). Ton nowadays is only a measure of weight. Tun originally referred to a barrel or large cask (usually of ale or wine) or a tub or chest. The problem is not serious when the two meanings could equally apply. So, when Falstaff is described as "a tun of man" (Henry IV Part 1, II.iv.436) or a whale "with so many tuns of oil in his belly" (The Merry Wives of Windsor, II.i.60), it hardly matters whether we are talking about liquid capacity or weight. But when the ambassadors bring Henry V a "tun of treasure" (Henry V, I.ii.256), the unaware listener might be surprised to see on stage quite a small gift.
David Crystal is author, with Ben Crystal, of Shakespeare's Words, published by Penguin