Ears to the side:

When it’s relaxed

Ears back:

When it’s alert or irritable

Ears forward:

When it’s attentive, interested, or alert. It is also a way of greeting each other.

Floppy ears:

Sign of tiredness, drowsiness or illness

Change the ear:

Sign of distrust

Wagging the tail:

Sign of restlessness, irritation (between horses it can be a sign of friendship)

Relaxed tail:

Sign of play, satisfaction

Tail between legs:

Sign of fear or pain

Tail raised:

Sign of excitement