Hopi (Uto-Aztecan)

List all the morphemes in the data, with their meaning or
function:

1)   ma:na mo:sat tu'i        'The girl bought a cat'
2)   ma:na po:kot tu'ito      'The girl went to buy a dog'
3)   po:ko ma:nat ku:ktini    'The dog will bite the girl'
4)   po:ko lolma              'The dog is pretty'
5)   mo:sa lolmatini          'The cat will get pretty'

ANSWER:  Compare the first two sentences, and see what
they have in common, and what is different:

1)   ma:na mo:sat tu'i

2)   ma:na po:kot tu'ito

The English glosses have in common 'the girl' and some form of
the verb 'buy'.  So either ma:na means 'the girl' and
tu'i means 'buy', or the other way around.  So, look for
another sentence about girls or buying.  None of the other
sentences have 'buy' or 'bought' in the translation, but (3) has
'girl':

3)   po:ko ma:nat ku:ktini

And this doesn't have exactly either ma:na or
tu'i.  But it does have ma:nat, which could be
ma:na with some kind of suffix.  So it looks like
ma:na must mean 'girl' or 'the girl'.
     Now remember that (1) and (2) have in common that they are
about a girl buying something.  So if ma:na means 'girl',
whatever else these sentences have in common must mean 'buy'. 
We've already seen that the only other element the two sentences
have in common is tu'i, so that is 'buy'.  So, we have
this much of (1) solved:

1)   ma:na mo:sat tu'i   'The girl bought a cat'
     girl         bought

So, by process of elimination, mo:sat must be 'cat'.  Then
look at (2):

2)   ma:na po:kot tu'i-to          'The girl went to buy a dog'
     girl         buy

Again, by process of elimination, po:kot must be 'dog',
and to must be a suffix that, when you add it to a verb,
means 'go to do' whatever the verb is.
     Now compare (2) and (3):

2)   ma:na po:kot tu'ito      'The girl went to buy a dog'
3)   po:ko ma:nat ku:ktini    'The dog will bite the girl'

po:ko must be the part of (3) that means 'dog', so again
we see a noun which in one sentence has a -t on the end,
and in another doesn't.  So, what is the -t?  Well, in
(2), ma:na 'girl' is the subject, po:kot 'dog' is
the object.  In (3), po:ko is the subject, and
ma:nat is the object.  So it looks like the -t
suffix may be used to mark the noun which is the object of the
sentence.  So now we want to check all the nouns in the data and
see if that hypothesis holds up.  It works in (4):

4)   po:ko lolma              'The dog is pretty'

po:ko is the subject, and it doesn't have the suffix.  And
if we compare (5) with (1), we see the same thing:

1)   ma:na mo:sat tu'i        'The girl bought a cat'
5)   mo:sa lolmatini          'The cat will get pretty'

When mo:sa 'cat' is the subject, as in (5), it doesn't
have the suffix; when it is the object, as in (1), it does.
     Now all that's left is the verbs.  Let's look at all the
data again:

1)   ma:na mo:sat tu'i        'The girl bought a cat'
2)   ma:na po:kot tu'ito      'The girl went to buy a dog'
3)   po:ko ma:nat ku:ktini    'The dog will bite the girl'
4)   po:ko lolma              'The dog is pretty'
5)   mo:sa lolmatini          'The cat will get pretty'

(4) is easy:  if po:ko is 'dog', then lolma can
only mean 'pretty'.  So comparing (4) and (5), we can see that
-tini, added to the verb, corresponds to 'will get' in the
English gloss.  We see the same ending on the verb in (3), and
there also the English gloss is in future tense.  So we can
identify -tini as a verb suffix marking future tense.  Now
all that's left is ku:k- in (3), and all that's left for
it to mean is 'bite'.
     So, the answer is:

          ma:na     'girl'
          mo:sa     'cat'
          po:ko     'dog'
          tu'i      'buy' or 'bought'
          ku:k      'bite'
          lolma     'pretty'
          -t        'object suffix'
          -to       'go to do'
          -tini     'future tense'

There is actually one more morpheme in the data--tu'i
actually consists of tu plus -'i 'past tense'.  But
there is no way that you could figure this out from the data here
(in many languages a bare verb automatically means past tense). 
To be able to analyze tu'i you would need to have a
present tense form of the same verb to compare with it.