Remedial French

I can read French reasonably well thanks to my already having grappled with Spanish and Portuguese, but I still have trouble with remembering the following little features:

QUI (subject) = who, which, that (of persons or things)
QUE (object) = whom, which, that (of persons or things)
DONT = of whom, of which (of persons or things)
LEQUEL = who, which, that (of two) (of persons or things)
DUQUEL = of whom, which, that (of two) (of persons or things)
AUQUEL = to whom, which, that (of two) (of persons or things)
DE QUI = whose, of whom (persons only)
À QUI = to whom, whose
QUOI = what (things only)
DE QUOI = of what (things only)
À QUOI = to what (things only)
QUEL, QUELS, QUELLE, QUELLES = which (persons or things)
LEQUEL, LESQUELS, LAQUELLE, LESQUELLES = sexed version of that or whom as in "La soeur de Jean, laquelle est riche".

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CELUI = this (masc)
CELLE = this (fem)
CEUX = this (masc pl)
CELLES = this (fem pl)
CE = this
CECI = this here
CELA = that there
ÇA = that

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NE verb PERSONNE = nobody (Je ne parle avec personne = I do not speak with anyone)
NE verb RIEN = nothing (Je ne pense rien = I do not think anything (nothing))
NE verb PAS ENCORE = not yet (Je ne joue pas encore = I do not play yet)
NE verb QUE = only (Je ne pense qu'à ma mère = I think only of my mother)

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EN = of something or some person and is masculine, feminine, singular and plural = equivalent of DE plus a noun

J'en ai = I have of it, of them
En avez vous? = Have you some of it? Have you (of) them?
Combien en avez-vous? = How much of it (or them) do you have?
J'en ai une douzaine = I have a dozen (of them)
J m'en souviens = I remember it (EN used for verbs that require "DE" after them)

Y = there and used as preposition of place and object of verbs that require à = the chief difference between Y and EN is that Y is seldom used for persons.

j'y avais = I am going (there)
j'y ai ètè = I have been (there)

nous leur y en avons parlé = we spoke of them of it there