Adverbs that indicate the degree or intensity of an adjective or another adverb are called intensifiers. Intensifiers tell to what extent a quality exists. They are placed before the words they modify.

Among the commonly used intensifiers are almost, very, rather, somewhat, too, completely, fully, extremely, so, and quite.

Examples:

Critics believe Katherine Hepburn's acting prowess was completely amazing.

She was so good that she won four Oscars just before her retirement from showbusiness.

Katherine was fully dedicated to acting and had a soaring career and a string of awards and nominations.

She had such star power that was so distinctly unrivalled in her time.