... park the other day, I saw a bird building a nest (= I was walking, the bird was building) According to Richards and others [longman; 1985]: The present participle is form by adding -ing to ... end in -ing. According to Quirk and others grammarians, word in -ing are considered as -ing participle. Quirk [longman; 1972] state the words such as “painting” or building in these examples ... “deverbal”. 14 Many other words in -ing are abstract mass noun such as “learning” “explaining”, “dancing”, “shopping”, etc.These words can be formed from any verb by adding -ing and inserting...