This is the 14651st most frequent German word.
monatlich
"Monatlich" means "monthly" in English.
In this sentence, 'monatlich' is used as an adverb to describe the regular interval of receiving the salary.
Ich bekomme monatlich mein Gehalt.
I receive my salary monthly.
Here, 'monatliche' is an adjective modifying 'Ausgabe', indicating that the edition happens on a monthly schedule.
Die monatliche Ausgabe der Zeitschrift ist sehr informativ.
The monthly edition of the magazine is very informative.
In this context, 'monatliche' is an adjective describing 'Zahlung', signifying that the payment recurs every month.