Here's a breakdown:
* He: This is the third person singular form of the verb "haber" (to have), indicating that the subject is masculine.
* estado: This is the past participle of the verb "estar" (to be), indicating a continuous state of being.
* soñando: This is the present participle of the verb "soñar" (to dream), indicating an ongoing action.
* contigo: This is the masculine singular form of "contigo" (with you), indicating that the speaker is talking about a specific person, likely the person they are addressing.
Therefore, the complete sentence translates to "I have been dreaming about you." It expresses a feeling of longing and possibly romantic affection.