Whenever you see what appears to be a verb in English ending in -ing, you have to be careful as to how you interpret the sentence, as it may wind up that this apparent verb is actually a noun or an adjective! In English, gerunds and present participles are formed by adding -ing to the infinitive form of the verb ("to surf" becomes "surfing"), or for verbs ending in -e, dropping the -e and adding -ing ("to love" becomes "loving"). A gerund is a verb that acts as a noun in sentence. A present participle is a verb that is used to make a verb phrase or an adjective.
Therefore an English verb ending in -ing can either be noun (gerund), an adjective (formed from a present participle), or a verb (a present participle). This all sounds a bit complicated, but if you look at some examples, it's pretty easy to tell the difference!
I've always loved surfing.
Caption 19, Kiteboarding, Rider Profile: Tom Court
What does he love? He loves surfing. In the above example, the subject of the sentence is "I," and the object of the sentence is "surfing." Since you can make a noun out of "the surfing" as used here, it is a gerund.
We watch a couple of surfing videos.
Caption 26, Kiteboarding: Sam Light Interview
What kind of videos is he watching? Surfing videos. Here it is clear that "surfing" is an adjective that is modifying the noun "videos."
The four of us have just been surfing different spots.
Caption 10, Naish SUP: Aloha Big Island!
What have they been doing? They have been surfing. In this last example, by pairing the verbs together, you get "have been surfing." This is the verb "to surf" in its form as present participle verb.
Write down some of your favorite verbs, add -ing to them, following the rules above, and search Yabla English to see them used in a real-world context as either a gerund, adjective, or present participle verb.