This thesis looks at the -ify and -ize suffixes and the semantic information in them. Beyond being derivational verbal suffixes, they make verbs whose meaning can be predicted and categorized into different groups. The current work on the suffixes describes these verbs as always denoting a change of state, but there are exceptions that express a stative meaning. This thesis investigates why the current work on these suffixes does not account for these exceptions, and seeks to expand the work to be able to express the semantic information of the suffixes. The work of Ingo Plag (1999) is particularly influential to this thesis, both in terms of its use of Jackendoff’s Conceptual Semantics as a tool to denote the semantic information of the suffix, as well as its comprehensive description of the polysemy of the suffixes. The thesis uses Jackendoff’s Conceptual Structures both as a theoretical background and as an analytical tool to describe the meaning of the verbs made with these suffixes. A Corpus was used to collect a full list of the stative -ify and -ize verbs.The stative nature of the exceptions is explained by the predicative relationship between the base and the subject NP. The base of the verbs with a stative meaning are also all relational bases, with one exception, such that the object NP acts as an argument of the base, specifically the possessor. With this in mind, the thesis concludes by proposing a Lexical Conceptual Structure (LCS) of the suffix that leads specifically to stative verbs. Furthermore, by arguing that the change of state denoted by most of the verbs with these suffixes can be described with Jackendoff’s Inchoative function, the thesis proposes a united LCS for the semantic information of the suffixes, which accounts for all verbs made with these suffixes.