to betray, to give away, to tattle
[verb]
[ver-klik-te, ver-klikt]

“Verklikken” or “klikken” is to give away information about a person to someone else. The informer is called a “verklikker”. The verb is often used when it concerns petty tale-telling by children. More serious betrayal is called “verraad”, the person who betrays is a “verrader” (“traitor”), and the verb is “verraden” (“to betray”). A synonymous verb which is slightly more informal than “verraden” is “verlinken”. Another verb which also means to reveal something is “verklappen”. Unlike “verklikken”, “verraden”, and “verlinken”, this verb doesn’t necessarily have a negative connotation.

Examples:
– “Het meisje verklikte tegen haar moeder dat haar broertje de koektrommel had leeg gegeten.” 
(“The girl told her mother that her brother emptied the cookie box.”)

– “Haar beste vriendin gaat vreemd met haar man; ze voelt zich verraden.”
(“Her best friend cheats on her with her husband; she feels betrayed.”)

– “In de Tweede Wereldoorlog werden Joodse families soms verraden door hun eigen buren.”
(“During the Second World War, Jewish families were sometimes betrayed by their own neighbours.”)

– “De crimineel verlinkte zijn handlangers in ruil voor strafvermindering.”
(“The criminal gave away his accomplices in exchange for a reduction of his sentence.”)

– “Je mag niemand verklappen wat we gaan doen, het is een verrassing.”
(“You cannot tell anyone what we will do, it’s a surprise.”)

– “In 2002 werd de kliklijn “Meld misdaad anoniem” landelijk ingevoerd.”

(“In 2002, the telephone number “Report crime anonymously” was introduced in the entire country.” Please note that “kliklijn” means “squeal-line”.)

Related words:
– “[Iemand] verlinken”: to betray [someone], to disclose against [verb] [verlinkte, verlinkt].
– “[Iets of iemand] verraden”: to betray [something or someone] [verb] [verried, verraden].
– “Verraad”: betrayal [noun] [het verraad, no plural].
– “Verrader”: betrayer [noun] [de verrader, de verraders].
– “Verklikker”: informer [noun] [de verklikker, de verklikkers].
– “[Iets] klikken”: to reveal [something], to tell [verb] [klikte, verklikt].
– “Kliklijn”: phonenumber that you can call if you want to reveal secret information [noun] [de kliklijn, de kliklijnen].

to be disappointing
[verb]
[te-gen-val-len, viel te-gen, is te-gen-ge-val-len]

“Tegenvallen” is used  when something does not answer to one’s positive expectations. The related noun is “tegenvaller”: disappointment/setback. When something is very disappointing, you can add a number of adverbs, see Extra.

You may often see a construction in the third person with an objective pronoun, for example: “Het valt me tegen dat…”, which translates to “It’s disappointing to me that…/It disappoints me that…”.

The opposite is the verb “meevallen” and the noun “meevaller”, which is used when something does not meet one’s negative expectations.

Examples:
– “Het miezert weer vandaag…dat valt tegen.” 
(“It drizzles again today…that’s disappointing.”)

– “De beurskoersen vallen weer behoorlijk tegen deze week.”
(“The stock exchange indexes are pretty disappointing again this week.”)

– “Het valt me vies tegen dat ik een bekeuring heb gekregen voor 3 km te hard rijden.”
(“It really disappoints me that I’ve had a speeding ticket for driving 3 km/h too fast.”)

Related words:
– Teleurstellen: to disappoint [verb] [stelde teleur, teleurgesteld].
– Teleurstelling: disappointment [noun] [de teleurstelling, de teleurstellingen].

Extra:
When something is very disappointing, you can add a number of adverbs. We’ve given the literal translation:
– erg tegenvallen: to be very disappointing.
– echt tegenvallen: to be really disappointing.
– zwaar tegenvallen: to be heavily disappointing.
– bijzonder tegenvallen: to be especially disappointing.
– vies tegenvallen: to be dirty disappointing.
– behoorlijk tegenvallen: to be quite disappointing.