pay attention to
Synonym discussion
Sense: idiom/1
'Pay attention to' is the most general of these expressions — it can mean watching, listening, or thinking about something. 'Watch' and 'listen' specify which sense you are using: you watch a football match but listen to a lecture. 'Concentrate on' is closer in meaning but emphasises mental effort and blocking out distractions rather than just directing your senses. 'Heed' is more formal and carries the idea that you will act on what you hear, such as 'heed a warning.' 'Notice' is weaker — it suggests becoming aware of something without necessarily focusing on it. For example: 'She noticed the crack in the wall' (she saw it in passing), but 'She paid attention to the crack in the wall' (she inspected it carefully).
Etymology
The verb 'pay' in this phrase comes from the 16th-century sense meaning 'to give or bestow' (as in 'pay a compliment' or 'pay a visit'). 'Attention' comes from the Latin 'attentio,' meaning 'a stretching toward' or 'mental focus.' The combined expression 'pay attention' — meaning 'to give your focus' — became common in English by the 18th century.