In the following presentation of tense and aspect, only verb forms in the indicative mood will be taken into account. Semantically, we can recognize various types of meaning associated with present tense, partly related to the type of verb in the verb phrase. I listen to the news while I have breakfast . Proverbs, eternal truths, etc. A stitch in time saves nine.
Oil floats on water .
Common to all these cases is the core meaning 'what is valid at the moment of speaking'. The perfective aspect The perfective aspect is used to indicate that an earlier action or state has relevance at a later reference point , or point of orientation . John lived in Paris for 20 years and John has lived in Paris for 20 years . John is polite. John is being polite.