On sabbatical leave from Instituto de Ciencias Físicas, Universidad Nacional Autónoma de México. Corresponding author: gabriel@fis.unam.mx.Abstract. We take a pragmatic, model independent approach to single field slow-roll canonical inflation by imposing conditions, not on the potential, but on the slow-roll parameter (φ) and its derivatives (φ) and (φ), thereby extracting general conditions on the tensor-to-scalar ratio r and the running n sk at φ H where the perturbations are produced, some 50 − 60 e-folds before the end of inflation. We find quite generally that for models where (φ) develops a maximum, a relatively large r is most likely accompanied by a positive running while a negligible tensor-to-scalar ratio implies negative running. The definitive answer, however, is given in terms of the slow-roll parameter ξ 2 (φ). To accommodate a large tensor-toscalar ratio that meets the limiting values allowed by the Planck data, we study a non-monotonic (φ) decreasing during most part of inflation. Since at φ H the slow-roll parameter (φ) is increasing, we thus require that (φ) develops a maximum for φ > φ H after which (φ) decrease to small values where most e-folds are produced. The end of inflation might occur trough a hybrid mechanism and a small field excursion ∆φ e ≡ |φ H − φ e | is obtained with a sufficiently thin profile for (φ) which, however, should not conflict with the second slow-roll parameter η(φ). As a consequence of this analysis we find bounds for ∆φ e , r H and for the scalar spectral index n sH . Finally we provide examples where these considerations are explicitly realised.