Mistakes will always be made in French, and now you can learn from them.
Wrong: Je suis lisant
Right: Je lis, Je suis en train de lire
Explanation: The present participle is far less common in French than in English.
In English, it's the verb form used for the progressive tenses, such as "I am reading" and "He was working."
French does not use the present participle in this way - in fact, French does not even have any progressive tenses.
The English present progressive is equivalent to the simple present in French, je lis, and the past progressive is equivalent to the imperfect, il travaillait.
If you want to stress the ongoing nature of the activity, you can use the expression être en train de (literally, "to be in the process of"): Je suis en train de lire, Il était en train de travailler