I know what you mean. English is a tough language. The two words are often used interchangeably. The difference between "ironic" and "ironical" is subtle. "Ironical" describes something having the characteristics of irony. "The speaker delivered a mocking, ironical talk". On the other hand, "ironic" relates to something unexpected or mocking. "It was ironic to work in the same office as my ex-girlfriend". The difference is the same as the difference between "economic" and "economical". Inflation is an economic problem. When I choose a cheaper brand of washing detergent in the store, my choice is economical.