- Wenn ich heute zum Supermarkt gehe, kaufe ich deutsches Bier!
- Falls ich heute zum Supermarkt gehe, kaufe ich deutsches Bier!
Q: “Ohhhh, stop, stop, stop. I’m happy that you enjoy your German beer. But what is the difference between those two sentences? “wenn” and “falls” mean exactly the same thing, they refer to a condition!” 
A: “True, both words refer to a condition, a possibility, a probability or a forecast. But there’s indeed a slight difference between “wenn” and “falls”. Do you want to know what the exact difference is?” 
Q: “Sure, tell me!”
A: "“falls” always refers to a possibility, not a probability. When you use “falls”, you always express an uncertainty of something. Imagine a cloudy, rainy day, and you want to barbecue with your friends. In this case, you would say “Falls es heute sonnig wird, grillen wir.” 
Or you know that German beer is rarely imported to your country. So, you may tell your partner “Falls es heute deutsches Bier im Supermarkt gibt, bringe ich es mit.” 
On the other hand, “wenn” expresses a probability of something. Imagine a cloudy, but also sunny day. Then you can say “Wenn es heute sonnig wird, grillen wir.” 
Or your favourite German beer is imported very often, but not always. Then tell your partner: “Wenn es heute deutsches Bier im Supermarkt gibt, bringe ich es mit.”" 
Q: “But isn’t that also a subjective issue, depending on your point of view?” 
A: "Absolutely correct, the use of “wenn” and “falls” depends on your point of view. You can express with those little words if you consider something probable (“wenn” = “if / when”) or just possible (“falls” = “in case of).” 
Q: “Thanks so much for the explanation.” 
A: “No problem. Next time we’ll speak about another important meaning of “wenn”: its temporal meaning!”
. En español diríamos en caso de “Falls” y si condicional “wenn”. Respondiendo a tu pregunta: Falls ich das Geld hätte, würde ich reisen 
Nach zweieinhalb Jahren. Das war schon genug!
!!!
