If there's one Japanese construction that would deserve a special prize for multifunctionality, it's the conditional. While expressing something akin to "If A, then B" occurs in almost every language, Japanese seems to have developed a very special fondness for such constructions.

The Japanese conditional clause normally takes one of the following forms at its end: -to, -eba, -tara or -nara(ba). The semantic differences are subtle, and it may take some time to get the right feel on which form to use when.

Take the clause 飲みすぎると (nomisugiruo to, if you drink too much). It will have quite different nuances in terms of causality, intentionality and (in)evitability when changed into 飲みすぎれば (nomisugireba), 飲みすぎたら (nomisugitara), or 飲みすぎるなら (nomisugiru nara). The hangover you'll end up with the next day will be just the same, though.