When I was learning Czech, I had some serious trouble with their words. For example, čtvrtek (their word for Thursday) is pronounced ĉtvrtek (notice how similar Czech spelling is to Esperanto). Also, they have:
čtyři - "ĉtyrĵi"
k, v (yes, just single consonant words)
potřebovat - "potrĵebovat"

Some of these sounds are fun to say, but it took me ages to learn to pronounce ř in a way I was happy with.

Pharoah:The accusative

You later mention that you learned Czech, and you're complaining about the accusative in Esperanto?!

Slavic languages have FAR harder declination, with multiple cases (7 in Polish, and I assume Czech is similar); many diverse endings depending on gender, case, root, etc; changes in the roots of the words, not just the end; inconsistent complex rules about which case to use; etc etc...

Esperanto's accusative "-n" is trivial in comparison...

I wouldn't say correlatives or the word knabo are particularly difficult, but it would be easier to just have a word for what, and a word for this. Then, you could make how with what way, when with what time, etc...

You effectively have that in Esperanto. Think of the correlatives as a pseudoprefix + a pseudosuffix.

"what" = "ki-"
"this/that" = "ti-"
"every" = "ĉi-"
"none" = "neni-"
"some" = "i-"

"way" = "-el"
"time" = "-am"
"reason" = "-al"
"general thing indicated" = "-o"
"one of a set indicated" = "-u"
"amount" = "om"

etc. Combine them at will, e.g.:

"how" = "kiel"
"when" = "kiam"
"this/that way" = "tiel"
"this/that time, then" = "tiam"
"at no time, never" = "neniam"
"some amount" = "iom"

etc.

Knabo just seems strange to me because it begins with kn. English words don't do that (kinfe and knight are pronounced najf and najt). But, even English has some sounds that are difficult for many people to pronounce. I just think it would be nice to not have so many weird consonant clusters.

"even English"... you say that as if you think English is mostly easy to pronounce for non-native speakers. In fact English is one of the harder languages to pronounce, in terms of having sounds that don't occur in most other languages. E.g. the English "r", and "th" (voiced and unvoiced), and "u" as in "russ". Depending on dialect, English has about 20 distinct vowel sounds, far more than many languages. And pronouncing English is made harder and more confusing by the unusually terrible lack of correspondence between the sound of a word and its spelling in English.

russ:

Knabo just seems strange to me because it begins with kn. English words don't do that (kinfe and knight are pronounced najf and najt). But, even English has some sounds that are difficult for many people to pronounce. I just think it would be nice to not have so many weird consonant clusters.

"even English"... you say that as if you think English is mostly easy to pronounce for non-native speakers. In fact English is one of the harder languages to pronounce, in terms of having sounds that don't occur in most other languages. E.g. the English "r", and "th" (voiced and unvoiced), and "u" as in "russ". Depending on dialect, English has about 20 distinct vowel sounds, far more than many languages. And pronouncing English is made harder and more confusing by the unusually terrible lack of correspondence between the sound of a word and its spelling in English.

Russ stop being the devil's advocate that's my job xD And I think you misunderstood what Pharaoh was trying to say (I'll get to that later)

Firstly, you say that as if English is uniquely hard. Last time I checked, most natlangs have the same problems. English is unique along with Danish and to a lesser extent French in that spelling vs pronunciation is not very simple. Additionally, English is now more or less similar to medieval or vulgar latin in that technically speaking it's hard to pronounce, but in practice it can be easy - in English we technically have '2' accepted 'r's (rolled and approximated), but we can understand the guttural 'r' and various other variants. We also have 'th', however we can for the most part understand 'th' if it is pronounced 'z/s' or 'd/t' (think about some Irish dialects for example). Vowels are also no problem, as we have so many different ways of pronouncing them that as long as you get the vowels somewhere in the accepted range you are fine. Basically English can be hard if you want to speak it properly, but in reality it can be treated as a loose group of closely-related languages (depending on your definition of a language) and therefore it can be quite an easy and forgiving language even if that is at the expense of English being slaughtered

ANYWAY my original point was that I think Pharoah was trying to say that to himself as a native speaker of English, some words in Esperanto seem difficult but at the same time words in his own language seem difficult and that it would be nice to have a language without those difficulties.

Of course Esperanto is easier than both Czech and English... I didn't mean to imply anything different. But, there are things about Esperanto that could be even easier. That's all I'm saying.

For the record, I didn't really learn Czech, I just learned as much as I could in a few months so I wouldn't feel like an idiot visiting Prague. I never managed to get a grip on their grammatical case system .

ANYWAY my original point was that I think Pharoah was trying to say that to himself as a native speaker of English, some words in Esperanto seem difficult but at the same time words in his own language seem difficult and that it would be nice to have a language without those difficulties.

Thanks, that was what I was trying to say. Sometimes I don't do the best job of expressing my ideas.