Conjunctions: als, wenn or wann
In these exercises, you must choose to use either als, wenn, or wann in each of the blanks. In English, we can use "when" to mean all of these things. However, they have very distinct meanings in German. Wann is a question word. It means "when" in reference to specific points in time, such as when a train arrives.
Wenn has several meanings. It can get confused with wann because it is used to mean "when" in the sense of "whenever," such as in the sentence "I will do it when I get there." It is also used when something happens regularly or consistently, such as in the statement "I bring my credit card when I travel." It is used with subjunctive statements, like "If I were rich, I would travel the world," as well as conditionals such as "If you trust me, give me your money." Als is used to refer to a general time in the past, as in the clause "When I was attending University..." It can also mean as.