Very broadly, if words are similar in some way, then there will be morphological generalisations associated with them, either in morphosemantics, morphophonology, or in morphotactics. Close examination of words shows that some generalisations are shared by all three sub-areas, for example the basic property of compositionality:
But words are not always fully or partially compositional. If they have no parts, they are trivially compositional (or not, depending on one's perspective). The spelling of Cupboard, i.e. "cupboard", is a function of the spelling of Cup, i.e. "cup", and the spelling of board, i.e. "board": they are joined by concatenation, which is conventionally interpreted as spatial order and spatio-temporal movement, i.e. writing or reading from left to right. But a cupboard is neither a cup nor a board, and the pronunciation is also non-compositional: /kVb@d/ is not a function of /kVp/ and /bO:d/, though there are clear resemblances. On the other hand, a dustman is (usually in our society) a man, and some relation to dust is involved; again, the phonology is also only partly compositional: not /dVstm@n/ but /dVsm@n/.
Semantically, a busdriver is a driver, and a birthday-cake is a cake; a generalisation can be made about the meaning of the whole implying the meaning of the head of the compound. But a paleface is not a face (though this could be a meaning of the word), and a fighter-bomber is both a fighter and a bomber.
From the point of view of internal structure, the way the parts of compounds are arranged is very similar, though different from derivation. And inflection is, with very few exceptions, phonologically and orthographically compositional; the concatenation function is coupled with regular adaptations to the morphophonological context. Semantically, inflection is also largely compositional: for instance, whether the Plural category means `more than one object of the class ...' depends on the meaning of the noun it is attached to. If the noun is countable, this is the meaning of the plural. If it refers to a substance, liquid or the like, the meaning is rather `more than one kind of the substance ...' (as with cheese), or, in some specific cases, `more than one separate quantity of the substance...' (as with `tea consumed in a café').
So although not all words have exactly the same properties, they may share some of the same properties, in semantics, in phonology, and in orthography. But semantics, phonology and orthographyare relatively independent in this respect, as the examples show, which implies that there are different kidns of generalisation.