The ultimate design goal of Sika is basically to make everything as simple as possible. I also try to rely on existing languages as little as possible. With this post, I'm going to try to explain the essentials. You can skip to the examples below first if you prefer.

The orthography here is IPA.

Every word has some number of inputs from before (taken from the most recent unused outputs) and outputs (which are determined by the inputs and the word used). Nouns are 0:1 (since they don't need inputs but have an output, their meaning), modifiers are 1:1, conjunctions are 2:1, and verbs are 1:0 (completing the sentence). Spaces are omitted between words with one output before and words with one input after. If that doesn't make sense, there'll be diagrams.

Let's start!

Let's start with something simple:

pensu. - It's a pen. pen-su

(I'm just borrowing the noun "pen" from English for now.) With "su", we can turn any description into a sentence. What we're saying here, more verbosely, is that the current topic of discussion is a valid case of the concept of a pen. While this might be way more technical detail than necessary for such a simple sentence, it can be helpful to fall back to this when things get complex.

penhisu. - It's not a pen. pen-hi-su

Negation is really simple; if we want to say something is not something else, just add "hi" to that something else. If we ever want to negate an entire sentence, we can just put "hi" right before "su". It's important to put "hi" right after the thing we want to negate, though, as we'll see.

penhusu. - It's probably a pen. pen-hu-su

The way "hu" works particularly highlights how the "case" way of thinking helps. Adding "hu" gives a concept that is most likely the thing we applied it to, in this case a pen. So what "penhu" describes is something that is probably a pen.

Things get interesting once we combine these two modifiers we've just learned, "hi" and "hu"; the order becomes important.

penhuhisu. - It's not something probable to be a pen. / It's not likely to be a pen. pen-hu-hi-su

penhihusu. - It's something probable not to be a pen. / It's unlikely to be a pen. pen-hi-hu-su

The first merely says that we have isn't a "penhu", something likely to be a pen. The second says that we are likely to have a "penhi", something that isn't a pen. This difference is as important as the difference between "You're not likely to get heads on a coin flip" and "You'll probably get tails".

We can also get something that just might be a pen with another "hi", since if it isn't likely to be a non-pen, it has a reasonable chance of being one:

penhihuhisu. - It might be a pen. pen-hi-hu-hi-su

Conjunctions

As exciting as pens are, it's about to get more exciting, since we're going to expand our temporary vocabulary moving into conjunctions:

pen pin hosu. - It's a pen or a pin.

pen---- ho-su
    pin 

"pen pin ho" can refer to a pen or a pin; it's just as right in either case. We can combine descriptions we want to be equally correct with "ho", no matter how long they are, if they'd work as sentences. If we want to combine three things, we could say

pan pen pin ho hosu. - It's a pawn, pen or a pin.

pan----------- ho-su
    pen---- ho 
        pin 

pan pen ho pin hosu. - It's a pawn or a pen, or a pin. (same meaning)

pan---- ho---- ho-su
    pen    pin 

If we want to combine descriptions with "and" instead of "or", that's "he" instead of "ho":

pen pinhi hesu. - It's a pen and not a pin.

pen------- he-su
    pin-hi 

Not just any pen

What if we want to say "A is B"? That's "ha", but we need to be careful:

pen pinhi hasu. - A pen is not a pin.

This means that any pen is not a pin. We're making a universal assertion about pens here. If we only wanted to talk about a certain pen, say the most important pen at the moment, the pen, that's

pensa pinhi hasu. - The pen is not a pin.

But what if we wanted to emphasize the pen we're holding over some other pen? There's a noun "ki" for just that, which means something we're indicating, pointing to, gesturing toward, etc.

ki pen hasu. - This is a pen.

What if it's the pen someone has been looking for all along?

ki pensa hasu. - This is the pen.

What if we wanted to use "this" like an adjective? All we have is a noun, right? Well, we can say "the thing that is this and a pen" as "ki pen he", so

ki pen he pensa hasu. - This pen is the pen.

ki---- he------- ha-su
   pen    pen-sa 

Or if you aren't too sure after all,

ki pen he pensa ha…hihuhisu. - This pen is the pen…maybe.

Thanks for reading! I might make this a series. If you have any questions, please ask them in the comments.