One’s something, specifying nouns: の

〜の = ‘s
Jo の neko = Jo’s cat
これは Joのneko です = This is Jo’s cat

Specifying nouns: [noun 1] の [noun 2] = specifying noun 2 using noun 1

eg. Nihon の neko (specifying neko) = Japan’s Cat (Cat of Japan) = japanese cat
Karate の sensei (specifying sensei) = Karate’s teacher (teacher of Karate) = Karate teacher

This/that/who

これ – This (close to the speaker)
それ – That (close to your counterpart)
あれ – That (Over There, away from both)

Used with は

これ は neko です = This is a cat
それ は neko です = That is a cat
あれ は neko です = That (over there) is a cat 

だれ = who

Jo は だれ です か = Who is Jo?

With の: この + noun = this car, that car, that car (over there)
(describing a noun)

この neko は kawaii です = This cat is cute

だれの = whose (これはだれのくるまですか = whose car is this ?) それは私のです = that is mine (you don’t repeat the noun when it’s clear what you’re referring to) 

Also combine with negative (じゃありません) or past positive (でした) or past negative (じゃありませんでした), see here.
あの neko は kawaii じゃありません = That cat (over there) is not cute

Textfugu Lesson

Related:

ここ = here (near me) 

そこ = there (near you) 

あそこ = over there

どこ = where 

Particle は/が: as for…

は (spoken “wa” not “ha”) = “as for”, “is”… Jo は student desu = as for Jo, he is a student
neko は kawaii desu = as for the cat, it is cute = The cat is cute.

は is placed after the subject.
Subject + は = as for [subject] / [subject] is…

Make it a question:
neko は ikura desu ka? = as for the cat, how much is it? = How much is the cat?

が is basically the same, but stresses the subject (the part BEFORE が). は stresses the part AFTER the は

は talks about something.
watashi は Jo desu = I am Jo

が identifies something.
watashi が Jo desu! = I am Jo

Use も instead of は to say “also” / “too”.

この ねこ は かわいい です。その いぬ も かわいい です。

this cat is cute. that dog is cute, too. 

Desu and the likes: Present/past positive and negative

です (des(u)) – it is, present positive
でした (desh(i)ta) – it was, past positive
じゃありません (jaarimasen) – it is not, present negative
じゃありませんでした (jaarimasendesh(i)ta) – it was not, past negative

Sentence order: 
です comes at the end of a sentence.

Noun + です = Noun, it is
山です = Yama desu = Mountan, it is = It is a mountain

Make it a question