"The man has shirts."
Translation:Tá léinte ag an bhfear.
Eclipsis occurs "after the prepositions ag, ar, as, le, mar, ó, faoi, roimh, thrí, thar, um if with the article an". Source is http://nualeargais.ie/foghlaim/nouns.php?teanga= , which, btw, is a wonderful resource when you're on the app. The table of contents in the section ONLINE GUIDE is clearly structured, so you find answers very quickly.
To be fair, from using the Duolingo app myself to start the course, I didn't learn until recently that the web version is more comprehensive and that there were even notes sections at all. Am really appreciating those who have taken the time to chime in on the threads with links, more directions, etc.!
eclipsis and lenition are mutually exclusive - it's one or the other, never both.
Words that start with f are eclipsed by bh.