Among the range of specific techniques circulating within current writing instruction guidance, sentence combining and sentence expansion stands out as one with a specific, notable endorsement: the What Works Clearinghouse, the Institute of Education Sciences' federal evidence-review body, has specifically recommended teaching students sentence-construction skills through techniques including sentence combining and expansion in its official practice guide, a level of federal evidence-review recognition that relatively few specific classroom writing techniques carry.

Sentence combining involves teaching students to take two or more simple sentences and combine them into a single, more sophisticated sentence using appropriate conjunctions, subordination, or other grammatical structures, while sentence expansion involves teaching students to add specific, meaningful detail to a simple sentence, answering questions like when, where, why, or how, to build richer, more developed sentences. Both techniques give students explicit, practiceable tools for building sentence-level sophistication and variety, rather than leaving this skill to develop only through incidental exposure to well-written text.

This technique's federal evidence-review recognition connects it directly to the broader sentence-level instructional emphasis currently gaining traction across multiple evidence-based writing approaches, reinforcing that sentence-level skill building isn't a fringe or unproven idea but a specifically recommended, evidence-supported instructional practice worth real classroom investment.

What makes this specific technique especially practical

Sentence combining and expansion exercises are genuinely low-cost and quick to implement, requiring no special materials beyond a set of simple sentences to work with, which makes them a particularly accessible entry point for teachers looking to build more explicit sentence-level instruction into their existing writing curriculum without a major overhaul. A brief, five-to-ten-minute sentence combining exercise can be woven into almost any content-area lesson, reinforcing both writing skill and subject-matter content simultaneously.

• Use brief sentence combining exercises regularly, taking two or more simple sentences and building them into one more sophisticated sentence
• Practice sentence expansion by having students add specific detail (when, where, why, how) to simple sentences
• Weave these exercises into content-area instruction, using simple sentences drawn from the actual subject matter being taught
• Recognize this technique's specific federal evidence-review recommendation as a strong signal of its research backing relative to less-vetted alternative techniques
• Track student writing over time for increased sentence variety and sophistication as a signal these exercises are producing genuine transfer

Why explicit federal evidence recognition matters for adoption decisions

With so many competing instructional techniques and commercial products claiming evidence-based status across the current writing instruction landscape, a technique with a specific, official recommendation from a federal evidence-review body offers departments and teachers a genuinely useful, low-risk starting point when deciding where to invest limited instructional time and professional development attention, since the underlying research vetting has already been done by an independent, rigorous review process.

This kind of specific evidence backing is also useful for departments building a case for curriculum or professional development investment, since pointing to a specific, named federal recommendation carries real weight in conversations with administrators or school boards evaluating competing instructional priorities.

A practical, well-supported place to start

For teachers and departments looking for a genuinely evidence-backed, low-cost entry point into more explicit sentence-level writing instruction, sentence combining and expansion offers exactly that: a specific, federally recommended technique that's simple enough to start implementing this week, without waiting for a larger curriculum adoption or professional development initiative to get underway first.