Primary progressive aphasia (PPA) is a clinical dementia syndrome with early symptoms of language dysfunction. Postmortem findings are varied and include Alzheimer disease and frontotemporal lobar degeneration (FTLD), both tauopathies and TAR DNA binding protein (TDP-43) proteinopathies. Clinical-pathological correlations in PPA are complex but the presence in the clinical profile of agrammatism has a high association with tauopathy. Grammatical competence is difficult to assess in the clinical setting with available methods. This article describes the Northwestern Anagram Test (NAT), a new clinical measure of sentence production. A total of 16 patients with PPA and their controls assembled single printed words to create sentences describing pictures. Northwestern Anagram Test performance was significantly correlated with a measure of sentence production and with aphasia severity but not with measures of naming, single word comprehension, object recognition, or motor speech. The NAT can be used to assess syntax competence when patients cannot be tested with measures that require intact speech production.