I saw a particularly interesting sentence in the wild just yet:
陛下は度々僕の部屋にやってきては手を握って何かを考えるんだ。
The interesting thing to me are the two te-forms in the sentence, with the former being made a topic, but the latter not. If my interpretation is correct, I would translate the above sentence as:
When His Highness sometimes comes into my room, he holds my hand, thinking of something.
But without the topic on the te-form, it would sooner be.
His Highness sometimes comes into my room and then holds my hand, thinking of something.
At least, the way I see it, the use of “〜は” moves the entire clause in the te-form to “background information”, as something the speaker considers as contextually existing information rather than new information, whereas what follows after it is the new information commented on the existing information, without it that clause would also be new information and would be translated more as the second sentence but I'm not sure if that interpretation is correct as all the other cases “〜ては” is encountered they're plain conditionals, usually quite simple, idiomatic ones such as “〜てはいけない” or “〜てはだめだ”
