To boil half a corn on the cob, the cooking time is generally shorter than for a whole ear but still within a similar range. Here are the key points on boiling corn on the cob (whole or halved):

• Bring a large pot of water to a rolling boil.
• Remove the husks and silk from the corn.
• If you have halved the corn cobs, add them to the boiling water.
• Boil the corn for about 3 to 5 minutes until the kernels are tender and bright yellow

• Some methods suggest boiling for 8 to 10 minutes for whole or halved corn, but 3-5 minutes is sufficient for tender, fresh corn and is often preferred to avoid overcooking

• After boiling, you can turn off the heat and let the corn sit covered in the hot water for a few minutes to keep warm and finish cooking gently if needed

In summary, for half an ear of corn on the cob, boiling for about 3 to 5 minutes in boiling water is enough to make it tender and juicy. Adjust slightly depending on corn freshness and size, but avoid boiling too long to prevent mushy kernels