radio

Everyday

1. A radio is a machine that receives sounds sent through the air by electric waves, so you can listen to music, news and talk. tree →
2. The radio is the programmes broadcast this way. tree →
3. Radio is a way of sending messages by invisible waves, used by pilots, police and ships. tree →
4. To radio someone is to send them a message by radio. tree →

In the lessons

In science, radio waves are invisible waves that travel at the speed of light; they carry sound for radios, signals for phones and TV, and are used in space. In safety, in a storm or emergency a battery or wind-up radio gives news and warnings. Walkie-talkies are small two-way radios. Phrases: on the radio, listen to the radio, turn on the radio, radio station, radio waves, radio contact.

Examples

• Dad listens to the news on the radio. tree →
• Turn the radio down, please. tree →
• My favourite song came on the radio. tree →
• The pilot radioed the control tower. tree →
• Radio waves travel through space. tree →
• We lost radio contact with the boat. tree →
• Keep a wind-up radio for emergencies. tree →

Note

Plural radios (not "radioes"). "On the radio" — with "on" and "the". Past: radioed. Radio waves are not the same as sound waves: sound cannot travel through space, radio waves can.