The genitive case is likely to cause trouble to English students because of its similarity to open compounds. To clarify the issue, a distinction has to be made.
In structures where two nouns are linked by the possessive determinative ‘s, the stress always falls on the second element (my brother’s wife / today’s paper) except for one important case: when the first noun functions as a classifier. In that kind of construction it is the first element that carries the stress, so if the expression is at the end of an IP, the LLI rule will be broken.
Swan (2003) illustrates this relation with the following pair:
The difference can be appreciated in the following example as well: