When dealing with older learners, explicit teaching of writing techniques is crucial. A solid foundation is necessary for learners with developmental language disorders to write.
Where do we begin? Rule of thumb: Always start simple and work towards more complex work. Always remember that promoting success at every level of learning is imperative to keep motivation high. Never rush skill building. Provide a variation of ways in which you teach a skill. Different activities each session to build the same skill. This helps with generalization of the skill and also application later on. Be purposeful when selection or developing materials.
I usually begin at the word level. Classification and word association must be taught. Exercises like these will fuel the writing process later on. Ample practice is required so building a resource bank is important for the teacher. It also helps speed up prep time.
Grammar, particularly the use of correct tenses, and singular / plural knowledge needs to be taught explicitly as well. Lots of practice is required. Again, I always begin on an isolated word level and work from there.
I find getting learners to read out loud tailored words / sentences helps the process along. Using two or more learning modalities is always better than one for learners with developmental language disorders. It can be faded out as fluency n accuracy reaches expected levels. Again keep it short and sweet to begin with.