Use 'have on' specifically to describe wearing clothes or accessories.

Clothing Only

'Have on' is used for what someone is currently wearing.

Present Tense

Use 'have on' to describe effects that are not immediately obvious.

Choose 'have on' when discussing an indirect or gradual influence.

Signal your skepticism or disbelief by asking if someone is 'having you on'.

Remember 'have on' is primarily British slang for teasing or joking.

Use 'have on' to talk about holding specific information about a topic.

Suggest more than just ownership; imply that the information is ready to be used.