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Usage and Grammar
Q. In the following sentence, “Ships arriving in Venice from infected ports were required to sit at anchor for forty days before landing,” is the word “landing” a verb form, or a verbal (gerund)? Why?
A. In your example, “landing” is a gerund—a present participle used as a noun. Note that it’s the object of the preposition “before”; only a noun (or a noun phrase) can be the object of a preposition. You can also compare “landing” to the other present participle in your example, “arriving,” which is used not as a noun but as an adjective: the participial phrase “arriving in Venice from infected ports” modifies the noun “Ships.” So “arriving” is a participle but not a gerund. For more on participles and gerunds, see CMOS 5.110–16.