Can someone explain when should I use כ , ך, ח? Similarly I get confused about א and ע.
Each letter has a different meaning.
Hebrew is a pictographic language, which means every letter represents a picture of something, that has meaning.
Aleph (א) = ox (strength, leadership...)
Bet (ב) = tent floor plan (family, house, in)
Ayin (ע) = eye (watch, know...)
Kaf (כ) = open palm (bend, open, allow, tame...)
Kaf sofit (ך) = the same as כ, but used only in the end of a word (called a "sofit")
Het (ח) = tent wall (outside, half...)
Nun (נ) = seed (to continue, heir, son...)
Shin (ש) = two front teeth (sharp, press, devour...)
Father (אב) = "strength of the house"
Son (בנ) = "continuation of the house" or "seed of the house"
Fire (אש) = "strong devourer" or "press strongly" (as it "devours" wood and things like this or because you have to press strongly two sticks)
There are 22 letters in the alphabet (or aleph-bet) and 5 of these letters have sofit forms (Hebrew: סופית, meaning in this context "final" or "ending"), here:
Mem (מ) = Mem sofit (ם)
Nun (נ) = Nun sofit (ן)
Kaf (כ) = Kaf sofit (ך)
Pey (פ) = Pey sofit (ף)
Tsadi (צ) = Tsadi sofit (ץ)
I hope it was useful and I didn't say anything wrong, because I am from Brazil.
Much love and blessings.
Your comment is very interesting, some info is new for me, though I have known the basic pictographic meanings of the letters. But I have to pay everybody's attention to the concept that it was more true for the Foenician alphabet, which was adopted by ancient Hebrews, in which most of the letters looked differently, then in modern square script. I could believe that the most ancient words , used to denote basic concepts, could be derived from pictographic past of the containing letters, but Hebrew of Torah has nothing to do with that. Each letter in Hebrew mean one specific sound (with minor deflections caused by dagesh and the letter position in the word), so the idea that Hebrew is pictographic is not true, the letters have pictographic origin (as many other alphabets imho), but letters mean sounds, not concepts, or images, like Latin letters (which has the same Foenician origin, but made much longer way) The only difference, Hebrew doesn't have letters for vowels, so when Ancient Greeks adopted Foenician alphabet, they deliberately assigned graphems to vowel sounds like Alef which meant some type of glottal voiceless sound, and later became mute (used like a placeholder for nikkud) turned into alpha with "ah" sound, consonant yud became iotta with "ee", hey became epsilon with short [i] sound(Foen. He looked very much alike to turned-over modern capital E) etc.
You can find out more googling Foenician alphabet (vs ancient greek - if you want to compare ). There's quite a lot information about it on the web
ך is called a"sofi" letter meaning it is only at the end of the wrote. As for the difference between these ח כ... You really just have to learn which is used based on the word. One of my Jewish friends said that caf (כ) is generally seem in cognate between Hebrew and English (this is her rule of thumb, not sure how accurate it is though). She also said that (ע) is seen more in cognate as well as more frequently used at the start of names (though there are exceptions, E.G. Emily is אמילי ).
Looks like because of the mixture of Latin and Hebrew letters the words kinda entangled, or what, couldn't make much sense of what you implied to write actually. Anyhow the end lettere is "sofit" (which literally means "ending " adj.) Like khaf-sofit (as far as I remember there cannot be kaf-sofit with k-sound, only with kh, like in "hat" at the end of Hebrew word), if the word ends with k, then it's kuf (kof), not kaf -it's another letter. And khet has no ending form, it looks the same, no regard, where it occurs.
Does anyone know why what I see when logged into the website is different from the level/what I see when using the app on my phone?