Masculine endings

Question 1

The following are masculine noun suffixes and other forms associated with masculine noun gender (click for examples and exceptions):

-ant, -ast, -ich, -ig, -ling, -or, -us

Examples: der Konsonant (consonant), der Kontrast (contrast), der Teppich (rug, carpet), der Käfig (cage), der Schwächling (weakling), der Faktor (factor), der Zirkus (circus)

Question 2

nouns formed from strong verbs

der Betrieb (operation, company, plant), der Biss (bite, from bissen), der Fall (case, instance; drop, from fallen), der Gang (gear; aisle)

Common exceptions:

das Grab (grave), das Leid (harm, sorrow), das Maß (measurement), das Schloss (castle), das Verbot (ban, prohibition)

Question 3

nouns ending in en, el, or er

der Hafen (harbor), der Flügel (wing), der Schatten (shade), der Fehler (mistake) and all nouns referring to people (most are from verbs), e.g. der Bäcker (baker, from backen), der Fahrer (driver, from fahren), but also der Onkel (uncle), der Vater (father), etc.

Some common exceptions

all gerunds such as das Essen (the food, eating) or das Fahren (driving); die Butter (butter), die Regel (rule), die Wurzel (root), die Geisel (hostage), das Fieber (fever), das Segel (sail), das Zeichen (sign, symbol)

NOTE: there are no -en nouns that are feminine!