Rule-based machine translation

Rule-based machine translation (RBMT; "Classical Approach" of MT) is machine translation systems based on linguistic information about source and target languages basically retrieved from (unilingual, bilingual or multilingual) dictionaries and grammars covering the main semantic, morphological, and syntactic regularities of each language respectively. Having input sentences (in some source language), an RBMT system generates them to output sentences (in some target language) on the basis of morphological, syntactic, and semantic analysis of both the source and the target languages involved in a concrete translation task.
History.
The first RBMT systems were developed in the early 1970s. The most important steps of this evolution were the emergence of the following RBMT systems:
Today, other common RBMT systems include:
Types of RBMT.
There are three different types of rule-based machine translation systems:
RBMT systems can also be characterized as the systems opposite to Example-based Systems of Machine Translation (Example Based Machine Translation), whereas Hybrid Machine Translations Systems make use of many principles derived from RBMT.
Basic principles.
The main approach of RBMT systems is based on linking the structure of the given input sentence with the structure of the demanded output sentence, necessarily preserving their unique meaning. The following example can illustrate the general frame of RBMT: 
Minimally, to get a German translation of this English sentence one needs:
And finally, we need rules according to which one can relate these two structures together.
Accordingly, we can state the following stages of translation:
Often only partial parsing is sufficient to get to the syntactic structure of the source sentence and to map it onto the structure of the target sentence.
Components.
The RBMT system contains:
The RBMT system makes use of the following: