The formation involves adding -ing to the bare infinitive:
The verb work is the base form of the verb, and working is the present participle:
The verb try is the base form of the verb, and trying is the present participle.
All English present participles are regular (in contrast to, for example, past participles forms).
Sometimes the present participle is irregular.
1. doubled letter
In these examples we can see that one of the letters (consonants) is doubled:
2. "e" removed
3. "ie" at the end changes into "y"