This problem concerns Lingala verbs. Each of the verbs in the lists below has three morphemes: a root; a morpheme indicating the person and number of the subject ('I', 'you:SINGULAR', 'he/she', 'we', 'you:PLURAL'); and a morpheme indicating some aspect of the time, the likelihood, or the desirability of the state or event. I'll refer to these three categories of morphemes as root, subject, and tense-aspect-modality (TAM). The following values of TAM appear in the lists below (you don't need to bother with what they actually mean): SIMPLE PRESENT (SIMP PRES) PRESENT PERFECT (PRES PERF), FUTURE (FUT), SUBJUNCTIVE (SUBJ).
Tone, marked by the presence (high tone) or absence (low tone) of an accent mark on vowels, is important in the lexicon and the grammar of this language; don't ignore it! To write accent marks, you can put them after the vowels. Don't type accented characters in your word processing program, then save them as text and upload them to Annotate; they won't show up in Annotate. If you want accented characters to display in Annotate, you have to use the HTML codes for the characters. If you know these, feel free to use them.
In the first list of verbs, all are in the SIMPLE PRESENT form. You just need to figure out what the subject morphemes are and where they come in the words.
I'll describe informally the process of how you might solve the problem.
Start by looking for some pairs whose meanings differ by only one morpheme. The first two words nakomo and tokoma differ only in that one has 'I' as subject, the other 'we'. The difference between the two forms is that the first begins with na, but the second begins with to. So tentatively at least we can assume the following:
Both of these morphemes come at the beginning of the word. Since morphemes belonging to the same set usually appear in the same place in the word, we can guess that the other subject morphemes will also appear at the beginning.
Before we go on, we might check to see if we are right so far by looking for other words with subject 'I' or 'we'. In fact all of the with subject 'I' begin with na, and all of those with subject 'we' begin with to.
Now we can either continue to look for pairs differing by only one morpheme, or we can try a different approach and look for all of the words containing a given unknown morpheme and see what they have in common. Let's try this second way and look for the morpheme meaning 'he/she'. The words containing that morpheme are asómba, akabola, asepela, atámbwisa, atála. These all share two things: they all begin with a, and they all end with a. But the a at the end could have nothing to do with 'he/she' because it is at the end of all of the words in the list (so probably has something to do with what all of the words share, that is, SIMP PRES). Based on what we already know, it is the beginning where we expect the subject morpheme to appear, so we can know conclude the following:
That leaves two more subject morphemes, 'you:SING' and 'you:PLUR'. We can do the same thing we did for 'he/she' and look for all of the words that share these morphemes. For 'you:SING' they are okóma, osómba, osepela, oyébisa, obóndela. These all begin with o. The words with subject 'you:PLUR' are all of the remaining words; they all begin with bo. So we can conclude
Thus all of the subject morphemes are prefixes, appearing at the beginning of the words.
The following list includes verbs in different TAM forms. (Only forms with subjects 'I', 'you:SINGULAR', and 'he/she' are included; the other subject morphemes behave similarly.) You need to figure out what the verb roots and the TAM morphemes are. (Also refer to the words in the first list.)
Now let's check different words with each of these root morphemes to see if they all share the forms that we're proposing. There are no others for 'ask', but for 'write' and 'arrive' the morphemes we proposed are found in all of the words. For 'divide' and 'wipe', however, there are a few words where the tones differ: okabólí, akabólí, and opangwísí. The tones on the first syllables of the forms we proposed agree (all are low), but on the second syllable, they are sometimes low and sometimes high. Maybe the tone on the second syllable is not part of the root morpheme, but part of the TAM morpheme instead.
Let's continue to look for more roots as we have been, this time looking for all words that share a particular root. For example, all words with the meaning 'buy' have sómb right before the final vowel. In several cases, we again discover that roots that appear to have more than one syllable have different possible tone patterns: for 'change' we find both bóngol and bóngól, for 'drive' both támbwis and támbwís, for 'enjoy' both sepel and sepél, for 'be;surprised' both tataban and tatábán. Again the first syllables always agree, while the other syllables can be either high or low. So here are the additional roots we propose, with the understanding that the tone on any syllables after the first is not specified in the root. (We can figure out the roots that have only example by looking for "minimal pairs" or "near minimal pairs" with other roots.)
Now let's try to figure out the TAM morphemes (the hardest part). Since we know whether the subject morphemes come, and we think we know what the root morphemes, the TAM morphemes should be whatever is left. One part that we haven't included in either the subject or root is the final vowel. Notice that this is a in all cases except when the TAM morpheme is PRES PERF. So we can propose that the following are at least parts of the TAM morphemes.
Now let's look at some "minimal pairs". The SIMPLE PRESENT and SUBJUNCTIVE look very similar, so they might be good to start with. One pair is nakoma and nákoma, the first SIMPLE PRESENT, the second SUBJUNCTIVE. It looks like the SUBJUNCTIVE makes the tone on the subject prefix high. Let's look at the other SUBJUNCTIVE examples to see if this holds. Sure enough, all have high tone on the subject prefix. So now there are two ways we can say this. One is to say that the tone on the subject prefix is specified by the TAM morpheme: it is low for SIMPLE PRESENT, FUTURE, and PRESENT PERFECT and high for SUBJUNCTIVE. The other is to say that subject prefix has low tone but that this gets changed to high in the SUBJUNCTIVE (an example of mutation). Given the data here, either would be reasonable.
Now let's try to figure out the future. Comparing it with the SIMPLE PRESENT (there are several "minimal pairs"), we can conclude that the FUTURE has an additional syllable -ko- following the subject prefix. (This is also a prefix because it precedes the root.)
Now for the PRESENT PERFECT. So far it seems to consist of just the suffix -í. But if we compare the SIMPLE PRESENT/PRESENT PERFECT "minimal pairs" such as okabola / okabólí, natatabana/natatábání, nabóngola/nabóngólí, atámbwisa/atámbwísí, we see that the suffix is not the only difference. In fact, if we look carefully, we see that for the PRESENT PERFECT, the root syllables following the first one always have high tone, whereas these same syllables always have low tone for the other TAM morphemes. Again there are two ways to describe this. Either the tone of these syllables is part of the TAM morpheme in all cases: low for SIMPLE PRESENT, FUTURE, and SUBJUNCTIVE and high for PRESENT PERFECT. Or these syllables have low tone in the root, and PRESENT PERFECT makes the tone high. Notice that the first option is appealing because it has those root syllables agreeing in tone with the suffix, an assimilation-like process.
So here are the TAM morphemes we come up with (one of several possible descriptions).
And now we should be able to put these together to make the novel words in 5.