Cleft sentences (main and subordinate clauses analysis)

It was because you are clever that I married you.

It was learning French that I found tiring.

What are the subordinate/main clauses. I am having really hard time analyzing the sentences above.

(1) [[It was because [you are clever]] [that I married you]].

(2) [[It was [learning French]] [that I found tiring].

Brackets surround the various clauses.

In both examples, the main (matrix) clause is the sentence as a whole.

Within the main clause, there is a head clause and a dependent relative clause, the former containing an embedded clause. Both head and dependent clauses are subordinate to the main clause.

In (1) the head clause is "It was because you are clever", within which is the embedded subordinate content clause "you are clever" functioning as complement of "because". The dependent relative clause is "that I married you".

In (2) the head clause is "it was learning French", within which is the embedded subordinate non-finite clause "learning French" functioning as predicative complement of "was". The dependent relative clause is "that I found tiring".

Note that in an it-cleft construction the relative clause does not form a constituent with its antecedent, i.e. it does not modify it.