Assigning a high probability to was following airline is straightforward since airline provides a strong local context for the singular agreement. However, assigning an appropriate probability to were is quite difficult, not only because the plural flights is quite distant, but also because the intervening context involves singular constituents. Ideally, a network should be able to retain the distant information about plural flights until it is needed, while still processing the intermediate parts of the sequence correctly. One reason for the inability of RNNs to carry forward critical information is that the hidden layers, and, by extension, the weights that determine the values in the hidden layer, are being asked to perform two tasks simultaneously: provide information useful for the current decision, and updating and carrying forward information required for future decisions.