[gwbas1c]

Look more closely at Latin gendering rules, not romance language gendering rules. In Latin, gender comes from the suffix.

It's typically carried over in suffixes from Latin: Words ending in "a" are feminine, words ending in "um" are masculine.

Or, look through common English names and see how often they follow Latin gender suffixes. Adam / Ada is an example. ("Am" is a male suffix.)

[davvolun]

I recall responding to the statement "English is just as gendered as...", but clearly that's not what you wrote. That's my fault.

[wbolster]

nit: the suffix -um in latin typically indicates a neuter grammatical gender. -us is usually masculine, and only in its accusative form it becomes -um. there are exceptions though, e.g. feminine 'manus' (hand). https://en.m.wikipedia.org/wiki/Latin_declension