We presume it would be a difficult task for a Mpongwe to explain the arbitrary law by which such changes are made. And yet he is as uniform and strict in his obedience to this law as if it were written out in an Mpongwe grammar, and taught in every village. His verb has four moods; viz., indicative, imperative, conditional, and subjunctive. The auxiliary particle gives the indicative mood its grammatical being. The imperative is formed from the present of the indicative by changing its initial consonant into its reciprocal consonant as follows:-- _tonda_, to love. _ronda_, love thou. _denda_, to do. _lenda_, do thou. The conditional mood has a form of its own; but the conjunctive particles are used as auxiliaries at the same time, and different conjunctive particles are used with different tenses. The subjunctive, having but one form, in a sentence where there are two verbs is used as the second verb.[92] So by the use of the auxiliary particles the verb can form the infinitive and potential mood. The Mpongwe verb carries four tenses,--present, past or historical, perfect past, and future. Upon the principle of alliteration the perfect past tense, representing an action as completed, is formed from the present tense by prefixing _a_, and by changing _a_-final into _i_: for example, _t[)o]nda_, "to love;" _at[)o]ndi_, "did love." The past or historical tense is derived from the imperative by prefixing _a_, and by changing _a_-final into _i_. Thus _r[)o]nda_, "love;" _ar[)o]ndi_, "have loved." The future tense is constructed by the aid of the auxiliary particle _be_, as follows: _mi be t[)o]nda_," I am going to love." We have not been able to find a Mandingo grammar, except Mr. MacBrair's, which is, as far as we know, the only one in existence. We have had but little opportunity to study the structure of that language. But what scanty material we have at hand leads us to the conclusion that it is quite loosely put together. The saving element in its verb is the minuteness with which it defines the time of an action. The causative form is made by the use of a suffix. It does not use the verb "to go" or "come" in order to express a future tense. Numerous particles are used in the substantive verb sense. The Mandingo language is rather smooth. The letters _v_ and _z_ are not in it. About one-fifth of the verbs and nouns commence with vowels, and the noun always terminates in the letter _o_. Here is a wide and interesting field for philologists: it should be cultivated.