"The father of my cousin's cousin is a pilot."
Translation:Faren til min fetters kusine er pilot.
Not sure about other countries, but in Greece (and possibly other Mediterranean areas) such person could be referred to as "uncle", if he was around the family a lot. Distant relatives and close friends of the parents are referred to as uncle (θείος/thios) and aunt (θεία/thia) by the kids, even though they're distantly or not at all related.
There's one for each gender, and one that's neutral, much like you have "sister", "brother", and "sibling" in English. Or "daughter/son/child".
en fetter = a male cousin
en/ei kusine = a female cousin
et søskenbarn = a cousin of either gender
You can always use the gender neutral version, but you need to know the other two as well.
There are, but they're the exception rather than the norm.
A noun like "fetters", which has had a genitive s added to its base form, does not take an apostrophe. Most nouns fall into this category, so the apostrophes are few and far between.
fetter -> fetters
Nouns that end in -s, -x or -z in their base forms do get an apostrophe added, but then the apostrophe goes at the very end of the word:
avis -> avis'
Marius -> Marius'
Bordeaux -> Bordeaux'
When dealing with acronyms, the genitive rules get a little complicated. Here are the acceptable formats, but note that most acronyms have to be capitalised, which means the third option will only rarely be available to you:
ACRONYMs (capitalised word, lower case s, no apostrophe)
ACRONYM'S (completely capitalised, apostrophe before s)
acronym's (all lower case, apostrophe before s)
If the acronym ends with an s, you only add an apostrophe at the end, as you would with any other noun: