1. to appreciate, to value, to esteem, to rate
[verb]
[waar-de-ren, waar-deer-de, ge-waar-deerd]

Here "waarderen" is used when you want to express appreciation or value/esteem something or somebody. You can also use "waarderen" in case of monetary value, see translation 2 below. Read the Extra below on what the equivalent of American-English "I appreciate it" could be in Dutch.

Examples:
– "Ik waardeer het enorm dat je vandaag gekomen bent." 
("I very much appreciate you being here today." Lit.: "…  that you have come today.")

– "Ik kan een sigaar op zijn tijd wel waarderen." 
("I appreciate (smoking) a cigar every so now and then.")

– "Het spijt me, maar uw bijdrage aan deze discussie wordt niet gewaardeerd." 
("I’m sorry, but your contribution to this discussion is not appreciated.")

– "Helaas moeten we vandaag afscheid nemen van een bijzonder gewaardeerde collega." 
("Unfortunately, today we have to say goodbye to a highly esteemed colleague.")

– "Over het algemeen voel ik me op mijn werk ondergewaardeerd."
("In general I feel undervalued at work.")

Related words:
– Op prijs stellen: to appreciate [verb] [stel op prijs, op prijs gesteld].

Example:
– "Uw aanwezigheid wordt niet op prijs gesteld."
("Your presence is not appreciated.")

Extra:
Sometimes people ask us how to say "I appreciate it" in Dutch. You can use the verb "waarderen" but mind that its usage is quite formal, i.e. when you say "ik waardeer het" or "het wordt gewaardeerd dat…" then you are making a bit of a strong statement, but it is the thing to say when you seriously want to thank somebody. If you however want to informally say "I appreciate it" or when the circumstances do not mandate a formal or very strong statement of appreciation, it is better just to say thank you (see the DWOTD "Dankjewel"), or you can use one of the following phrases:

– "(Dat is) tof van je": that is nice of you [informal].
– "Dat is (bijzonder) aardig/vriendelijk van je/u": that is (really) nice of you.

2. to value, to estimate, to appraise, to rate, to mark
[verb]
[waar-de-ren, waar-deer-de, ge-waar-deerd]

Here "waarderen" is used in the context of monetary value, or when you want to rate the quality of something. There is a strong link with the noun "waarde": value.

Examples:
– "De film ‘Gran Torino’ wordt door de recensenten hoog gewaardeerd." 
("The film ‘Gran Torino’ is highly rated by the critics.")

– "Nederlandse huizen zijn over het algemeen overgewaardeerd en het wordt tijd dat de prijzen gaan dalen!" 
("In general Dutch houses are overvalued and it is about time that the prices will drop!")

Related words:
– Waarde: value [noun] [de waarde, de waarden]. Note that the word is used for both "monetary" and "moral" value.
– Prijs: price, cost [noun] [de prijs, de prijzen].
– Taxatie: assessment, appraisal (of an object) [noun] [de taxatie, de taxaties].