For a non-native speaker, particular a German one, "great" is a nice word.
First, it's simple, and probably one of the first words of the English language that can be memorised and pronounced properly. It is related to similar sounding words in other Germanic languages. In German, we have groß, which can mean large, tall, big, or great. It's today mostly a word of physical measurement, unless used with a person or thing of value. A große(r) Frau/Mann addresses a great (wo)man, ein großer Schatz can be a great (meta-physically) or big (mere amount) treasure. All "XXX the Great" are der/die Große in German, such as Alexander, Katarina, Friedrich etc.
The first time I was on my own in England (2-week pupil exchange), I used it excessively, lacking the vocabulary to express myself otherwise.
Very much like my favourite Turkish word, güzel, which can mean anything profoundly positive between nice, beautiful and ... well, great. No Turk will be insulted if you call his wife güzel (use with care for unmarried daughters, depending on the area) or the Blue Mosque, Turkey (Turkiye) itself is güzel, naturally (well, it was, a certain president is doing a great job changing this). It's easy to pronounce (for a German) and has a diphtong! My other favourite word, with four üs is Müdürlüğü, the (head) administration office – a word demonstrating the logic of the Turkish language: müdür – leader, boss, etc.; -lü + what a person does/thing is like, -ğü – the place where it happens.
And this brings us to Donald The Trump(el), and how he ruined it. Obviously also lacking the vocabulary (you know: I am a very, very educated person, so intelligent, I just passed the test for not suffering from Alzheimer with full points. Great! #MAGA), he used "great" to address (incomprehensive selection):
- The probably worst performance ever during a presidential campaign; he only won the primaries because the Republican system ensures anyone getting roughly 30% of the votes will become candidate when the others are even worse (see the Green Papers for how it works); and became president falling short of roughly 3 million votes. Surely the greatest victory ever! And his greatest [Republican] electoral college since Reagan (Trumpel got 306; 304 voted for him) was 120 heads short compared to Bush the Elder (Clinton had 370, + 5 Mio votes; and Obama 365, + 10 Mio votes, first time; even Bush the Younger fared better: only 271 electors, but also only half a million short on votes; and it still bugs the Big Baby according to his tweets).
- Anyone he just appointed to office, great, great guy, or endorsed, great, great guy, is doing a great work #MAGA. Many of which are then doing a poor job, sad! (e.g. Sessions also started as a great, great man), or have not done anything so far ...
- That he'll build a great, great wall to Mexico (and makes Apple to pay for it, sort-of) instead of the fence already there.
- Making America Great Again! Well, it's really impressive to see that unemployment dropped from over 40% (felt, infamous Gingrich interview; Trumpel on the topic) to 4.5% doing a really, really great, great job here. Equally great are the percussions of stripping down Obamacare, which – as promised – Big Baby Trumpel – replaced by something much greater. You'll see, eventually.
- Stripping down EPA, so it cannot do its work and reducing the size of protected land so mining companies can have easy access at some point in the future, great opportunity here.
- Hire a two-employee company with links to the Secretary of the Interior to re-install the electric grid in the colony (Puerto Rico), which are doing a great job.
- Helping the "conservative" (conservation means to protect, not to destruct) and "libertarian" establishment (i.e. billionaires backing the Republicans and funding creationists: consumers don't need education, only voters do) to make the U.S. even less social than it already is. Really great! From a European perspective, the U.S.'s social system is a really great mess (inefficient, overly expensive, and lacking minimum safeguards) and a great, great embarrassment for one of the richest countries in the world.
In short, the Trumpel made the word "great" a synonym of mediocre, bad, nasty, unbelievably stupid, or a vehicle to hide-up (very badly, I may say) an obvious lie. These times, when you use it, great always seems to come in quotation marks ... yeah, really "great".
Trumpelchen literally took the grandeur from "great". So sad!!!
So now, when I have to adress something that would have done with "great" before (e.g. great thing, great job, great picture, that's great), I hesitate. I don't want to depreciate something by using the deflated "great", and have to think of something else. "Nice" has become something of a standard in my English correspondence/conversations (it was Good Omens that pointed out the versatile use of "nice" to me: A Nice and Accurate Description of the Things to Come by Agnes Nutter, Witch; always wanted to entitle a paper A Nice and Accurate Phylogeny of ..., but my co-authors didn't allowed me to).
But there are more alternatives, and other contexts. Native English speakers will probably know them (unless they enjoyed the same great education as the U.S. president), for all others here are some suggestions from my (analogue) thesaurus (The Original Roget's International Thesaurus. Revised and Updated 6th Edition). Quite a list for "great":
- as noun: skilful person (section 413.14) — ace, star, crackerjack, dab, topnotcher, first-rater, whizz, flash, pisser [really?! probably not a good choice when conversing with an American], world-beater, hot rock [a must for a geologist like me!];
- in the sense of "great keyboard" (711.17) — organ, keyboard wind instrument [I learned playing the piano, but didn't know people call organs "great keyboards". Second thought: Trumpel might, after visiting Notre-Dame in Paris. Visited the big, big church, great, great keyboard, loved to play, but French president Marrone (or something like that), great man, tiny hands, soft, so soft handshake, not let me. So sad!];
- as adjective: pregnant (78.18) — gestating, breeding, teeming, parturient, wearing her apron high [possibly bit outdated], gravid, heavy, big-laden;
- in the sense of "grand" (247.6) [here we go] — considerable, consequential, mighty, powerful, strong, irresistible [Now I understand why truly great men can grab them by the pussy], intense, total, full, serious, heavy, deep;
- in the context of "chief" (249.14) — main, principal, paramount, leading, prime, supereminent, preponderant;
- in the sense of "large" (257.16) — sizeable, big, grand, tall, considerable, goodly [Hm..that sounds classic: "Oh my goodness, what a goodly bosom" may not yet qualify for #MeToo; no warranties taken!], tidy, substantial, bumper [hm... as in "ouch...what a bumper speed bump"?], good-sized;
- in the context of "authoritative" (417.15) — clothed/vested/invested with authority [something great Trumpel should have per office, but does not wield in reality], commanding, imperative, powerful, potent, influential, prestigious, weighty, momentous [see also "chief"]
- in the sense of "magnanimous" (652.6), e.g. great-souled/-spirited — generous, liberal [to use Nelson Muntz' catchphrase: "haha", see Liberal Denial post], big-/large-hearted, noble-/high-minded, idealistic, benevolent, noble, princely, lofty [Is this the reason lofts are called lofts? They charge usually princely prices for them...], sublime;
- in the sense of "eminent" (662.18) — high, exalted, elevated, enskyed, awesome, enobled, aggrandised, deified, apotheosised [see also "magnanimous" and "grand"]
- in the sense of "important" (997.17) — major, consequential, significant, world-shaking, earthshaking, high-powered, double-barrelled, bigwigged, mega [see also "grand" and "chief"];
- in the sense of "excellent" (999.13) [this is a fun-list, only non-formal terms] — swell, dandy, bitchin', jim dandy, neat, neato, super-duper [and I thought that's a Swedish invention], fab, fantabulous, marvy, gear, ducky, dynamite, killer, hot, nifty, sexy, spiffy, nobby, peachy, delicious, scrumptious, hunky-dory, stunning, corking, smashing, rum (Brit.), bonzer (Austr.), bang-/jam-/slap-up, (A-)OK, copacetic [that doesn't strike me non-formal...], phat;
- as interjection: bravo! (509.22) — well done!, ¡ole!, bene!, hear, hear!, hurrah!, whizzo!, swell!, atta[?!]boy!/-girl/-baby/-gal, encore!, bis!, congratulations!