Elements of Theft and Appropriation
Theft requires proving someone dishonestly appropriated property belonging to another with intention to permanently deprive them of it. It's not as simple as just "taking something" - each element must be carefully established.
Appropriation means assuming the rights of an owner, and you don't even need to physically touch something. In Morris, simply switching price labels in a shop counted as appropriation, even without leaving the store. The key case R v Pitham and Hehl shows that selling furniture that wasn't yours is appropriation.
Here's what might surprise you: appropriation can happen even when the owner consents. In Lawrence, a taxi driver taking £7 instead of 50p was still theft, whilst Gomez established that even with the owner's permission, theft can occur. Even accepting gifts can be appropriation if the circumstances are dodgy, as seen in Hinks where someone with low IQ was persuaded to give away £60,000.
Property includes both tangible things (your phone, clothes) and intangible assets (trademarks, bank accounts). However, you cannot steal electricity, dead bodies, or confidential information - though you can steal the paper that information is written on. Wild flowers and animals can sometimes be taken legally, but not for commercial purposes.
Quick Tip: Remember that appropriation is ongoing - it doesn't just happen at one moment, which affects where and when someone can be prosecuted.