Although it was raining, we still went for a walk. Here although introduces the surprise: the rain did not stop them.
You can also put it in the middle: She went to work although she felt sick.
Although the shop was crowded, the cashier found my size in minutes. The surprise is the fast service despite the crowd.
I finished the report although my internet kept cutting out. Here although sits in the middle of the sentence.
Although he's rather shy, he's not as bad as he used to be. In this use it works a bit like but, adding a true statement after the first one.
We can meet on Friday although I'd prefer Saturday. Try swapping in your own plans: state the option first, then the preference with although.
Although I could see the sun in the sky, the weather was still chilly. A short although clause at the front sets up the unexpected result.
From plans and messages
Although we agreed on Monday, I can only make Thursday now. Send this when plans shift and you still want to sound polite.
I'll pick you up at eight, although traffic might make us a bit late.
Please send the invoice today although payment won't go out until next week. A work message where although separates what you're asking from what can't happen yet.
Although I'd love to come, I'm working that evening. Use this shape to decline an invitation softly: the although clause carries the regret, then the real reason follows.
We'll walk although it looks like rain. Handy in a chat about plans; the weather doubt is mentioned, then the decision stands anyway.
Although the deadline is Friday, I'd like a draft by Wednesday. State the deadline, then add the stricter request that matters more to you.