PRESENT PROGRESIVE
Exceptions
To form the gerund of a verb in English you just have to add the ending -ing to the infinitive, without needing to modify the spelling of the word. However, there are some exceptions:
If the infinitive ends in -e, it is necessary to eliminate this vowel before adding -ing. In the case of -ee, -oe or -ye, the e is maintained.
E.g. come – coming
agree – agreeing
In words with a short pronunciation vowel before a final consonant, the final consonant is doubled. This is not so with the final consonants -w, -y, or -x.
E.g. sit – sitting
In British English, you have to duplicate the final l after a vowel. This is not the case in American English.
E.g. travel - traveling (British English), traveling (American English)
Verbs that end in -ie replace these vowels with one and before adding the ending -ing.
E.g. lie – lying
Temporary markers
Temporal markers allow us to identify the verb tense that should be used in a sentence. These are some of the most frequent time markers that are used in English with present continuous.
E.g. At the moment, now, just now, rigth now. etc.
USE
The present continuous is used in English to express:
Events that take place at the moment of speech.
E.g. Look! James is taking a picture of another tourist.
Plans or appointments scheduled for the near future.
E.g. He is meeting his friend Brad tonight.
Temporary actions
Brad is working there as a tour guide over the summer.
Current events.
E.g. He is staying at a youth hostel.
Situations that indicate evolution or change.
E.g. The town is becoming more and more popular because of its beautiful beaches.
Conjugation
To conjugate a verb in present continuous, use the auxiliary verb be and the main verb in gerund, that is, adding the ending -ing to the infinitive.
E.g. He is speaking