shirt
The French word for 'shirt' is 'chemise'. It is used in the same context as in English, to refer to a piece of clothing worn on the upper body. However, remember that French nouns have genders, and 'chemise' is a feminine noun, so you must use feminine adjectives to describe it.
I really like your shirt.
This sentence is used to express admiration for someone else's shirt. In French, 'ta chemise' refers to 'your shirt'. 'J'aime beaucoup' is a commonly used phrase to express 'I really like'.
The shirt is blue.
This sentence is declaring the color of a shirt. 'La chemise' refers to 'the shirt', and 'est bleue' means 'is blue'. This is a basic structure used in French to describe objects.
He is wearing a red shirt today.
This sentence is to describe what someone is wearing. 'Il porte une chemise rouge aujourd'hui' translates to 'He is wearing a red shirt today'. 'porte' is the French verb for 'wears', and 'aujourd'hui' means 'today'.