In Milton's sonnet, "How Soon Hath Time," the following rhyme scheme is used:

a b b a a b b a c d e d c e

This is an Italian Sonnet with an octave (first eight lines) and a sestet (last six lines).  The octave reveals the problem.  The speaker relents the fact that he is not developing mentally, and possibly spiritually and poetically, as quickly as he wishes, and that he is showing little promise.

The "Yet" begins the sestet, revealing that whatever he will or will not do, whatever he will accomplish, is adequate, since it is up to Time and Heaven anyway. 

The words that rhyme in the octave are:

youth/shew'th/truth/endu'th

and

year/career/near/appear

These are regular rhymes except for shew'th and endu'th.  Depending on one's pronunciation, these are slant rhymes, or rhymes that are not exactly regular.  It appears possible that even these could be pronounced with the same vowel sounds as youth and truth, however, which would make them regular, as well.

The words that rhyme in the sestet are:

slow/so   ev'n/Heaven    high/eye

These are regular rhymes, also, with the possible exception of ev'n/Heaven, which again, could be pronounced as slant rhyme or regular.