The Present & Infinitive
In English, we make heavy use of the present progressive when describing activities that we are in the process of doing.
I am reading philosophy.
He is doing the dishes.
In French, the simple present (see present conjugations) will always be used. In English you also could use the simple present but it sounds Shakespearean.
Je lis de la philosophie.
Il fait la vaisselle.
If you wish to emphasize that you are right in the middle of doing something in French use the phrase 'en train de'.
Je ne peux venir. Je suis en train de peindre ma maison.
I cannot come. I am right in the middle of painting my house.
The simple present in French is also used to express actions that you are doing in the near future. In English we would probably use the present progressive.
The French and English present are used in the same way to express habitual actions and universal truths.
Les français aiment beaucoup le football.
Soccer is very popular in Europe.
The infinitive form is totally without tense. The infinitive is the non conjugated form of the verb. When two verbs are used together, the first verb marks the tense and the second will be in the infinitive form.