At a networking mixer, you will often want to share information you have heard or gathered from others. In English, you might say "I hear that...", "I gather that...", or "I understand that...". In Icelandic, this is expressed with the impersonal middle-voice phrase mér skilst.
Because this is an impersonal construction, the person doing the understanding is in the dative case (mér). The verb skilja (to understand) is in the middle voice (skilst), giving it a passive, evidential feel—literally, "it is understood to me."
The Subjunctive After "Mér skilst að"
When you add að (that) to introduce the information you heard, the verb in the following clause takes the subjunctive mood. This happens because you are reporting indirect speech or conveying information you did not experience firsthand.
For example, the indicative er (is) becomes the subjunctive sé.
You will frequently see this combined with the dummy subject það to mean "there is" or "it is." In these cases, það er becomes það sé.
Other Verbs in the Subjunctive
Regular verbs also take their subjunctive forms after mér skilst að. For many common verbs, the third-person subjunctive simply ends in -i (for example, byrjar becomes byrji, and ætlar becomes ætli).
When discussing what will happen in the future, the auxiliary verb mun (will) changes to its subjunctive form muni.