Opara v. Attorney-General of the Federation  9 NWLR (Pt. 1569) 61 at 109, paras. A-E, per Kekere-Ekun, JSC:
“On the contention that the appellant who speaks Pidgin English does not understand English Language, this court in a recent decision in Olanipekun v. The State (2016) LPELR-40440 (SC) @ 8-9, D-A; (2016) 13 NWLR (Pt. 1528) 100 at p. 118, paras. C-D, per Aka’ahs, JSC had this to say:
“It is erroneous to assume that people who communicate in Pidgin English do not understand proper or Queen’s English especially in Nigeria. The use of Pidgin English allows for free expression without minding the grammar which is usually employed in proper English. Consequently, a statement which was said have been recorded in Pidgin does not require translation into proper English and any statement made in Pidgin can be recorded in proper English.”
The reasoning above is equally applicable in the circumstances of this case. The fact that the appellant speaks Pidgin English does not mean she cannot understand proper or “Queen’s English”. I also venture to say that the fact that a person cannot read or write does not mean he/she cannot understand English when addressed in that language.”
What happened in the above case was that the Appellant was charged on a 9 count charge of procurement of persons for prostitution, forceful or deceitful inducement of persons and confinement or detention of persons against their will, contrary to and punishable under sections 15(a), 19(b) and (c) respectfully of the Trafficking in Persons (Prohibition) Law Enforcement and Administration Act, 2003 (as amended).
The Appellant was found guilty and was consequently convicted and sentenced to 14 years imprisonment. Her appeal to the Court of Appeal was dismissed. On a further appeal to the Supreme Court, learned Counsel for the Appellant contended that the Appellant’s arraignment was irregular as the provisions of section 215 of the Criminal Procedure Act was not followed. It was argued that the Appellant was an illiterate and speaks only Pidgin English and thus did not understand the language of the Court which was proper English Language.
The Supreme Court had no difficulty in discountenancing the argument as it held that the Appellant never complained that she did not understand the language of the Court or that technical terms were used which she did not comprehend. The apex Court was further strengthened in its view when it found that the record showed that the charge was read and interpreted to the Appellant in the presence of her Counsel and no complaint was raised at the earliest opportunity either by the Appellant or her Counsel.
It is clear that the only contention of the Appellant’s Counsel was that since the Appellant speaks only Pidgin English, the arraignment which was in proper English must therefore be quashed. The Supreme Court however did justice to such erroneous reasoning. (See the quotation above).
Of course the apex Court noted the opinion of Oputa, JSC (of blessed memory) in Kajubo v. The State  1 NWLR (Pt. 73) 721 at 737, where the revered Jurist noted that “…It is a notorious fact that English, the language of the court, the language in which charges and informations are drafted, is not the mother tongue of Nigerians. It is also correct that most Nigerians are illiterate in English and that even those of them who are literate may not easily follow and comprehend the language of the court…”
However, the Court was of the position that the circumstances which led to the nullification of the trial of the accused person in that case was not present in the instant case, as the charge was well read and interpreted to the Appellant. See p. 106 of the report. I agree.
One interesting implication of the position of the Supreme Court to note is that it is a more arguable point for an accused person to contend that he/she only speaks any other language or indigenous language like Igbo, Hausa, Yoruba, Fulfulde, Efik, Bini, etc. than to argue that he/she speaks only Pidgin English.
Authorities on proper and valid arraignments are numerous. See Hassan v. Federal Republic of Nigeria  6 NWLR (Pt. 1560) 64 discussed here.
You may read the following write-ups – The Origins of Pidgin English; Broken English, Pidgin English, and Nigerian English and Pidgin.