face to face—
1. addressing smb. directly:
- There are some students who are shy and will only talk to you online, but others would rather talk face to face.
2. in direct encounter with a person:
- She toadied to her superiors when she really came face to face with them.
head to head—
1. in direct confrontation or conflict:
- On the same day the two candidates go head to head in their only joint televised debate.
2. competing so closely that the lead is virtually indistinguishable:
- He made an announcement saying that the two candidates were head to head so it wasn’t time to celebrate yet.
Note: The expression does not correlate in meaning with its formal French counterpart tête-à-tête—a talk in private with only two people present:
- He had tête-à-tête with Maung Aye, the powerful Burmese army chief, when he visited Thailand.