Which phrase indicates a fee simple determinable?

The phrase "So long as" is a clear indicator of a fee simple determinable. This type of estate is characterized by an automatic reversion of the property to the grantor if a specified condition is not met or if an event occurs. The use of "so long as" sets a clear boundary for the duration of the estate, suggesting that the estate will exist only under that condition.

For example, if a property is granted to someone "so long as" they use it for agricultural purposes, the ownership continues only while that condition is satisfied. If the grantee fails to adhere to the condition, the property reverts back to the original owner.

In contrast, phrases like "under the condition that" may indicate a conditional estate but do not specifically denote the automatic reversion aspect that characterizes a fee simple determinable. "At the discretion of the owner" suggests more of a personal choice or subjective management rather than a property interest with specific conditions tied to ownership. "Until revoked by the owner" implies a more flexible or revocable situation that does not align with the rigid conditions of a fee simple determinable. Thus, "so long as" distinctly captures the nature of this type of estate.