Learn Swedish: Vi behöver mycket pengar till huset. - We need a lot of money for the house.

We use mycket (a lot of / much) for uncountable things, and många (many) for things we can count. Just like in English, money is treated as an uncountable amount, so we use mycket.

But doesn't the -ar ending mean pengar is a plural word?

Yes, grammatically pengar is plural (the singular word en peng means a coin). However, when talking about wealth in general, it acts as an uncountable mass. This makes it a special case where a plural word takes the uncountable mycket.

The translation says 'for the house'. Why use till instead of för?

Prepositions rarely match up perfectly between languages! When money or an item is intended for a specific purpose, recipient, or destination, Swedish usually uses till. You can think of it as needing money to go 'to' the house.

Just as a refresher, why does 'the house' end in -et here?

The base Swedish word for house is an ett-word: ett hus. To say 'the house', you attach that article to the end of the word, making it huset.