English pairs certain adverbs with certain adjectives, and the adverb is fixed, not free to swap. Highly recommended means strongly praised as worth doing or using, something you'd tell a friend not to miss. Absolutely essential means completely necessary, something you cannot manage without. Both highly and absolutely are neutral intensifiers, natural in speech or writing. Absolutely also partners with adjectives that describe an extreme, such as shocking, where it again means completely. The catch is that the everyday word very does not fit here: "very recommended" sounds wrong to native ears.
Adverbs that intensify adjectives
highly recommended /ˈhaɪli ˌrekəˈmendɪd/ — The workshop is highly recommended for new students.
absolutely essential /ˌæbsəˈluːtli ɪˈsenʃl/ — Clear instructions are absolutely essential in an exam.
Not ""The workshop is very recommended."" — say ""The workshop is highly recommended."". "Recommended" collocates with highly, not "very." The adverb is fixed.
Try it: Clear instructions are completely necessary in an exam. They are ___. (absolutely essential / highly essential / deeply essential) Answer: absolutely essential — The fixed collocation is absolutely essential, meaning completely necessary. "Highly" pairs with "recommended" and "deeply" with feelings like "affected", but "essential" takes absolutely.
Adverbs for strong feelings
Strong emotions have their own adverb partners. To be bitterly disappointed is to feel very let down and unhappy because something you hoped for did not happen. To be deeply affected is to be strongly moved in your feelings by something you saw or heard. The feeling each adverb carries is the key: bitterly always carries something unpleasant, so it fits negative words like disappointed, regret and cold, never happy ones. Deeply is neutral but serious, used when something reaches your emotions, and it also partners with sorry and grateful. Neither pairs with plain very or with highly.
bitterly disappointed /ˈbɪtərli ˌdɪsəˈpɔɪntɪd/ — Hiroshi was bitterly disappointed when the concert was canceled.
deeply affected /ˈdiːpli əˈfektɪd/ — Mei was deeply affected by the speaker's story.
Not ""Mei was bitterly affected by the story."" — say ""Mei was deeply affected by the story."". "Affected" takes deeply. Bitterly goes with unpleasant words like disappointed and cold, and "affected" is neutral, so it does not fit here.
Try it: Hiroshi had really hoped to go, so when the concert was canceled he was ___. (bitterly disappointed / highly disappointed / strongly disappointed) Answer: bitterly disappointed — The natural collocation for strong disappointment is bitterly disappointed, feeling very let down. "Highly" and "strongly" pair with other adjectives, but "disappointed" takes bitterly.
Fully: completely
Fully means completely, with nothing left out, and it partners with adjectives that describe a total or finished state. A hotel that is fully booked has no free rooms left. Someone who is fully qualified has completed all the training a job requires, and someone who is fully aware of a risk understands it completely. Perfectly works the same way in perfectly normal, which means completely ordinary and nothing to worry about.
fully booked /ˌfʊli ˈbʊkt/ — The Senfarren View Hotel was fully booked for the weekend.
fully qualified /ˌfʊli ˈkwɑːlɪfaɪd/ — Camila is fully qualified to teach the advanced class.
fully aware /ˌfʊli əˈwer/ — Lars was fully aware of the risks before he signed.
Not ""The hotel was highly booked for the weekend."" — say ""The hotel was fully booked for the weekend."". Booked takes fully, because the meaning is completely, not strongly.
Try it: Camila has finished every course and exam the job requires. She is ___ for the position. (fully qualified / absolutely qualified / deeply qualified) Answer: fully qualified — Fully qualified means she has completed everything the job asks for, so fully is the adverb that means with nothing missing. "Absolutely" pairs with extreme adjectives such as essential or shocking, and "deeply" is used for feelings, so neither describes a finished set of qualifications.
Extremely, incredibly, totally
Three more adverbs mean very. Extremely and incredibly are close in meaning and often swap places: a situation is extremely serious when it needs attention right away, and an exam is incredibly difficult when it is far harder than expected — either adverb sounds natural with either adjective. Totally is different: it suits adjectives with no middle ground, where something either is so or is not, which is why an answer that is not partly right is totally wrong.
extremely serious /ɪkˈstriːmli ˈsɪriəs/ — The flooding at Senfarrow Brook was extremely serious.
incredibly difficult /ɪnˈkredəbli ˈdɪfɪkəlt/ — Mateo found the final exam incredibly difficult.
totally wrong /ˈtoʊtəli rɔːŋ/ — Yasmin checked the schedule and found that her notes were totally wrong.
Not ""Your answer is fully wrong."" — say ""Your answer is totally wrong."". Wrong takes totally. Fully goes with a finished state, such as booked or qualified.
Try it: Mateo studied for weeks, but the final exam was far harder than anything he had practiced. It was ___. (incredibly difficult / fully difficult / bitterly difficult) Answer: incredibly difficult — Incredibly difficult means far harder than expected, and incredibly is one of the two adverbs that fit difficult, alongside extremely. "Fully" means completely, which does not describe a degree of difficulty, and "bitterly" carries an unpleasant feeling, so it pairs with words such as disappointed or cold.