The infinitive is the most basic form of a verb. In Spanish, infinitives always end in -ar, -er or -ir, with -ar being the most common. An infinitive by itself does not indicate tense nor who or what is performing the action of the verb. In both English and Spanish, the infinitive can often function as a noun. In Spanish, such a noun is always masculine and is usually used in the singular form. The Spanish word for infinitive is infinitivo. Other examples of infinitives in Spanish are hablar, viajar, comprender, and resistir.
1 The kidneys are a pair of bean-shaped organs that lie on either side of the spine in the lower middle of the back. 2  Each kidney weighs about 5 ounces and contains approximately one million filtering units called nephrons.  Each nephron is made of a glomerulus and a tubule.
Depending on the level of the body, the following organs may lie next to the kidney 1  : Psoas major muscle (medial to both kidneys). 2  Quadratus lumborum muscle (posterior to both kidneys). 3  Spleen, colon (lateral/anterolateral to left kidney) and liver and colon (lateral/anteroletral to the right kidney).