"I opened the big window and let the cool wind in."
大きいな まどを あけ すずしい かぜを 入れました。
I am confused by the あけ - I would have expected the te-form of あける, i.e. あけて, since this seems like a succession of actions.
What function does the あけ serve here - why is it used?
あけ is similar in use to あけて in the sense that it connects the cause (opening the window) and the effect (the cool wind blowing in), but differs in “subjectivity”, which means that あけて is used to imply that the cause will “direct” the situation towards the effect, while the use of あけ describes the effect as something that occurs due to the natural flow of events following the cause, and in a manner less forceful than that implied when using あけて. This is the reason for the absence of the connective て, because of the need to weaken the connection between the cause and effect.
But don't we have a cause and effect here? No open window, no cool breeze!
Could you think of an example that illustrates this use of the stem better? I know that, when actions are unrelated, i.e. not sequentially or causally linked, you use a verbform with あり at the end, right? So this "stem" form is some sort of middle ground?
Cause and effect are there in both cases, but the subjectivity (the role of the cause in the effect) is different.
Case 1: 彼女は結婚して名字がかわりました (she got married, so her last name changed )
Case 2:彼女は結婚し忙しくなりました (she got married, so she became busy)
In both cases the cause and effect are connected, but the degree of "directness" of the influence of the cause on the effect is different.
I know that, when actions are unrelated, i.e. not sequentially or causally linked, you use a verbform with あり at the end, right? So this "stem" form is some sort of middle ground?
あり is the "stem" form of the verb ある (あります)
あけ is the "stem" form of the verb あける (あけます)
Though I'm not too sure what you were describing with "use a verbform with あり at the end", this use of あけ is likely the same concept as what you were saying about あり.
No, that's not what I meant. I'll have to look this up in Minna no nihongo: there is a way to connect actions that are not sequential (there even are examples in the Duolingo course: the sentence is something like "on weekends I watch tv and go shopping"). In that case you don't use the te-form but another form that ends (!) in あり. I'll have a look tomorrow.
Funnily enough, almost the very first question I encountered on the reverse tree tonight was the following one:
"He speaks, she listens. "
Just thought this example might add a bit more of an idea of how this type of sentence works. ^^