It is pertinent to observe that the vagaries of the English language grammar constitute a major problem in the teaching and learning of English in a second language situation like Nigeria. The inherent structural irregularities within the English language have made it difficult for users and learners of English to grapple with the unconventional patterning that are experienced at the various levels of linguistic analysis. These irregularities that are inherent within the grammar of English, which impede teaching and learning, have always been mentioned in passing by scholars. There is hardly any systematic attempt at isolating and describing them for pedagogic purposes. This paper, therefore, surveys and isolates these irregularities at the levels of spelling, phonology, and morphology, and describes them in order to aid the teaching and learning of English in ESL situations like Nigeria. It was observed that these problems are prominent, for instance, in "-ough" forms which can be pronounced in so many different ways: (/o-[near-close back rounded vowel]/ as in "though", /[close back rounded vowel]/ as in "through", /[lambda]-f/ as in "rough", /[open back rounded vowel]-f/ as in "cough", /[open-mid back rounded vowel]/ as in "thought", /[alpha-near-close back rounded vowel]/ as in "bough", /[schwa]/ as in "thorough" or even where some letters are silent in pronunciation as in "knee" and "knock", "science" or in "ghost" amongst others.