Are these words still used in Am. English?
I constantly come up with words that sometimes are not really used in American English anymore (or at all...). Words like ''to inculcate'' or '' to covet.'' I started using the website called ''wordandphrase'' but recently I came across some words on Forbes that I've never seen before.

to mount up - ''The tasks quickly mount up...'' Can I use this word interchangeably with ''to mount''? For example: ''The tension before the exams was mounting/mounting up.''

backlog - This is the first time I've seen this word and I've read dozens of articles about time/project management. If you don't use this word on a daily, what other word can I use instead?

The word ''aim'' can be used interchangeably with ''goal'', right?

perfunctory - His answer was incredibly perfunctory.

apprehension/apprehensive - The sales representative dispelled all of their apprehensions.(?) or ''I am really apprehensive about moving across the country.''

bleak - Their future is looking really bleak.

Question

Are these words still used in Am. English?
I constantly come up with words that sometimes are not really used in American English anymore (or at all...). Words like ''to inculcate'' or '' to covet.'' I started using the website called ''wordandphrase'' but recently I came across some words on Forbes that I've never seen before.

to mount up -> ''The tasks quickly mount up...'' Can I use this word interchangeably with ''to mount''? For example: ''The tension before the exams was mounting/mounting up.''

backlog -> This is the first time I've seen this word and I've read dozens of articles about time/project management. If you don't use this word on a daily, what other word can I use instead?

The word ''aim'' can be used interchangeably with ''goal'', right?

perfunctory -> His answer was incredibly perfunctory.

apprehension/apprehensive -> The sales representative dispelled all of their apprehensions.(?) or ''I am really apprehensive about moving across the country.''

bleak -> Their future is looking really bleak.

Answer

I use 'mount up' or 'mount' - but I'm not American. Forbes is an American publication, and if they use 'mount up' then I guess it's ok in America too.

Inculcate/covet/backlog/aim/apprehensive/perfunctory/bleak  are all still used here in the UK.  Inculcate, perfunctory, apprehensive are quite formal. Covet is a little old-fashioned, but does a useful job. Bleak is a wonderfully descriptive word. Backlog is less formal, and I use it every week as I always have a backlog of work!

These words are all in use. Covet is the one you probably won't need very much, unless you covet your neighbour's Ferrari. (I don't think that was the original biblical quotation!).

Answer

"to mount up" I have never used this phrase. But I would say "the tensions are mounting" and not "tensions are mounting up". Not really sure on an example or anything because I have never said "mount up"

"backlog": when you have a bunch of things you need to do and you can't keep up. This word would probably only be used in the situation you described: product management. It may also be used to describe a "backlog of events" if say, you had to investigate something going wrong (like your computer crashing). However, I'm not too sure that usage is correct, I've definitely heard it used.

"aim" I don't think I would use "aim" interchangeably with "goal", but you could (it's correct). Rather, I would "aim for a goal" i.e. "I aim to be fluent by next summer".

"perfunctory" There won't be many people that even know what this means haha

"apprehensive" Of all the words on your list, I think I use this one the most. If I'm feeling nervous or something I might say "I'm feeling a little apprehensive about this test"

"bleak" "The future looks bleak" is just about the only time I've actually heard that word used. Maybe "it looks bleak and gloomy outside" but I don't think you'll hear this word outside of those phrases.