In winter one of the easiest trees to identify is the Sweet Chestnut. You can’t id the tree from a distance by its shape but if you look closely at the bark, buds and shoots and then look for old leaves and old fruit underneath the tree, you can be sure that it is a Sweet Chestnut. All these photos are taken form the Tree Guide UK app.
Mature trees have very distinctive bark. The ridges swirl round the trunk like this. This is an extreme example but most old trees show ridges that spiral round the trunk.
The buds are very small and red/brown.
The shoot is ridged.
Old leaves can often be often be found on the ground under the tree. They stay like this all winter.
Sweet Chestnut husks look like this. The nut will have been eaten, probably by squirrels but husks like this are found all winter under the tree. They are very spiky to the touch.