For example, comparing English and German:
- English has simple plurals. In regular cases you add an s or es, and the number of exceptions is limited. Chair, chairs. Book, books. Jacket, jackets. In German plurals are, for all practical purposes, completely irregular: Stuhl, Stühle. Buch, Bücher. Jacke, Jacken.
- English does not generally have gendered nouns, nor an equivalently complex replacement.
- English does not have cases, nor an equivalently complex replacement.
- As a result of those two, the English words a and an correspond in German to ein, eine, einen, einem, einer and eines.
- English has almost the same tenses as German, but let's take the verb to run in the present tense: I run, you run, he runs, we run, they run. In German, laufen: Ich laufe, du läufst, er läuft, wir laufen, ihr lauft. Rather then two forms, there are five.
- English does not have formality encoded in its grammar.
It's pretty hard to say that German isn't objectively harder than English.