that (introduces a subordinate noun clause and connects it to its parent clause) / Substitutes for another, previously stated conjunction. / when, no sooner / Links two noun phrases in apposition forming a clause without a (finite) verb, such that the complement acts as predicate.

introduces a comparison; (comparisons of superiority or inferiority) than / introduces a comparison; (comparisons of equality) as / (used with ne) only, just; but, nothing but

(slightly formal, accusative) The inanimate direct-object interrogative pronoun. / (slightly formal, nominative) The inanimate subject or predicative interrogative pronoun.

(accusative, relative) The direct object relative pronoun.

because

so that

(slang) sod all, naff all, jack shit (nothing)

whereas, while, whilst

although

let's hope (that) / provided (that), as long as