Tall
High, Expensive
い adjective
This is a single kanji with an い on the end, meaning you know it's probably an adjective. What's the adjective form of tall or expensive? It's the same: tall or expensive.
Weird that this word means both of these things, yeah? Just imagine money piled up to be really tall. That money is tall because it needs to buy something expensive.
Since this word consists of a kanji with hiragana attached, you can bet that it will use the kun'yomi reading. You didn't learn that reading with this kanji, so here's a mnemonic to help you:
Being tall is really expensive because you have to buy a tall car (たか). If it's not a tall car then your tall body won't fit inside, and those tall cars are expensive!
あの高いビルの中に本社があります。
There's the HQ in that tall building over there.
この車は高いですが、デザインがいいです。
This car is expensive, but it has a good design.
ビジネススーツに百万円は、高すぎるよ。
A million yen for a business suit is too expensive.