Verbs in the present continuous tense are formed by adding "ing" to the base verb form. For verbs ending in e, just add ing. For verbs ending in a consonant preceded by a vowel, double the final consonant and add ing. Exceptions to the doubling rule include verbs ending in c, ie, and y. Verbs with two syllables where the last syllable is stressed also double the final consonant before adding ing.