NOTE: The answers for remainders below indicate whether the remainder is vested or contingent. You are not responsible for distinguishing between vested and contingent remainders, since we did not cover that distinction in class. I included the information merely for the sake of completeness; you need not be concerned with it.
1. A has a life estate and the grantor has a reversion in fee simple absolute. (Note: in all later answers, the fact that a future interest is "in fee simple absolute" will be assumed and not stated. If the future interest is other than fee simple absolute, that fact will be noted.)
2. Since the time Halley's Comet will return is well known to astronomers, this is a fixed-term leasehold estate in A. The grantor has a reversion.
3. A has a fee simple determinable. The grantor has a possibility of reverter.
4. The answer is the same as No. 3.
5. A has a fee simple subject to condition subsequent. The grantor has a right of entry.
II. Remainders, vested and contingent.
6. A has a life estate. B has a vested remainder for life; it is vested because the taker is ascertainable and there is no expressed condition precedent. However, it is obvious that if B does not survive A, B's remainder will never become possessory, so it is sometimes classified as vested subject to complete defeasance. The grantor has a reversion.
7. A has a life estate pur autre vie ("for the life of another"), with B as the measuring life. C has a vested remainder.
8. A has a life estate. B has a vested remainder for life. C has a vested remainder in fee simple absolute.
9. A has a life estate. (a) If B has no children yet, the remainder to the children of B is a contingent remainder. (b) If B has two living children and no deceased children, the two children have a vested remainder subject to "open" or to "partial defeasance," so long as B is still living. Once B dies (or nine months after B dies, if B is male), the remainder becomes indefeasibly vested. (c) If B has two living children and one deceased child at the time of the conveyance, the answer is probably the same as (b). It is extremely improbable that the grantor intended to make a conveyance of any interest to a deceased person, and even if the grantor did so intend, the validity of such a conveyance is very doubtful.
10. A has a life estate. B has a contingent remainder, since it is subject to a condition precedent that B survive A. O has a reversion. If B does not survive A, B's remainder will fail when A dies, and O's reversion will become possessory. If B does survive A, the condition precedent associated with B's remainder is satisfied and B's remainder will vest in possession.
11. A has a life estate. B has a vested remainder, subject to complete defeasance.
12. A has a life estate. If A has had any sons, the eldest son has an indefeasibly vested remainder. If A has had no sons, the remainder is contingent, since the taker is unascertainable. Note that there's no condition of survivorship of the son; A's first-born son will be entitled to the remainder even if he dies before A (in which case, the son's heirs, devisees, or grantees will take possession when A dies). If A has no sons now, its possible that A will never have any; hence, the grantor has a reversion.
13. A has a life estate. The remainder to the children of B who survive A is a contingent remainder, since it is subject to an express condition precedent. The grantor has a reversion, since it is possible that no children of B will survive A.
14. A has a life estate. The remainder to the children of B who survive B is a contingent remainder, since it is subject to an express condition precedent. The grantor has a reversion, since it is possible that no children of B will survive B.
15. A has a life estate. B has a contingent remainder. Grantor has a reversion
16. A has a life estate. B has a contingent remainder. Grantor has a reversion.
17. A has a life estate. A's surviving children have a contingent remainder, since it is subject to a condition precedent of survivorship. B also has a contingent remainder, since it, too, is subject to a condition precedent (the "nonsurvivorship" of A's children). This is sometimes termed a case of "alternative contingent remainders."
18. A has a life estate. B has a vested remainder, subject to complete defeasance. (It is subject to a condition subsequent, another "divesting condition.") The grantor has a reversion.
19. A has a life estate. B has a vested remainder, subject to complete defeasance. It is subject to a condition subsequent. C has (believe it or not!) an executory interest. The reason is that the common law judges viewed C's interest as divesting or "following" B's interest, and since B's interest is a fee simple, and since a remainder cannot "follow" a fee simple, C must have an executory interest. In other words, B's and C's interest are not alternative contingent remainders, since B's remainder is vested; and since it is vested, an interest that divests it is an executory interest, not an alternative contingent remainder.
20. A has a life estate. The heirs of B cannot be ascertained so long as B is still living; hence their remainder is contingent. Once B dies, B's heirs are ascertainable and their remainder becomes indefeasibly vested. The grantor has a reversion, since it is possible that B will have no heirs at all.
III. Executory Interests and Remainders.
21. A has an executory interest. The grantor has a fee simple subject to executory interest. (Yes, it's true that the grantor's interest is limited to a definite time period, and looks like a fixed-term leasehold estate. But it's still classified as a fee simple!)
22. A has a fee simple subject to executory interest, and B has an executory interest.
23. A has a life estate. B has an executory interest (not a remainder, since it is separated from the life estate by a "built-in time gap.") The grantor has a reversion, which will take in possession for one month after A dies.
24. A has a fee simple subject to executory interest, and B has an executory interest.
25. A has a defeasible life estate, subject to an executory interest. B has an executory interest. (It's not a remainder, since it may cut short the prior life estate.)
26. A has a fee simple subject to executory interest, and B has an executory interest.
27. A has a defeasible life estate subject to executory interest, and B has an executory interest. Grantor has a reversion.