Vatican website translation:
The two parts which, in a certain sense, go to make up the Mass, namely, the liturgy of the word and the eucharistic liturgy, are so closely connected with each other that they form but one single act of worship. Accordingly this sacred Synod strongly urges pastors of souls that, when instructing the faithful, they insistently teach them to take their part in the entire Mass, especially on Sundays and feasts of obligation.
56. Duae partes e quibus Missa quodammodo constat, liturgia nempe verbi et eucharistica, tam arcte inter se coniunguntur, ut unum actum cultus efficiant. Sacra proinde Synodus vehementer hortatur animarum pastores ut, in catechesi tradenda, fideles sedulo doceant de integra Missa participanda, praesertim diebus dominicis et festis de praecepto.
Slavishly literal translation (kindness of Jonathan Day):
The two parts that, in a certain sense, stand together as the Mass – none other than the liturgy of the word and the eucharistic liturgy – are so closely connected with each other that they accomplish one act of worship. Hence this sacred Synod strongly urges pastors of souls that, when delivering the catechism [or “handing over catechesis” jmj], they painstakingly teach the faithful to take part in the entire Mass, especially on Sundays and feasts of precept.
Roman Rite Catholics of a certain age may remember being taught that they fulfill their Sunday Mass obligation if they are physically present in church for the Offertory, the Consecration, and the [priest’s] Communion. The residue from this teaching is sometimes seen in congregations where assembly members receive holy communion and then exit the church building before the final prayers of the Liturgy of the Eucharist and of the Concluding Rites. Art. 56 once again highlights the importance of attending and celebrating the Liturgy of the Word (and, presumably the Introductory Rites) for a comprehensive ritual engagement with the Mass.
Pray Tell readers may wish to discuss how effectively their congregations have been catechized about the intimate union of the Liturgy of the Word and the Liturgy of the Eucharist accomplishing “a single act of worship.” Do members of the assembly regularly come so late to worship that they miss the Introductory Rites and/or the Liturgy of the Word? Do members of the assembly leave so early that they miss the concluding prayers of the Liturgy of the Eucharist and/or the Concluding Rites? If so, why so? What might be done to “painstakingly” convince the faithful “to take part in the entire Mass”?