guilty
[adjective]
[schul-dig]

"Schuldig" translates to "guilty". The related noun is "schuld", which translates to "guilt" or "debt".

If you’re "onschuldig", you’re not guilty or innocent.

Examples:
– "Ik voel me schuldig omdat ik Sara’s verjaardag vergeten ben." 
("I feel guilty because I forgot Sara’s birthday." Lit.: "I feel myself guilty…")

– "De verdachte werd schuldig bevonden aan moord." 
("The suspect was found guilty of murder.")

– "Wie heeft er een scheetje gelaten?" – "Oeps…schuldig…" 
("Who farted?" – "Oops…guilty…")

Expressions:
– "Het antwoord schuldig (moeten) blijven": to not be able to give an answer.
– "Iemand iets schuldig/verschuldigd zijn": to owe someone something, to be in someone’s debt.

Example:
– "Hoeveel ben ik u schuldig?" – "EUR 9,80."
("How much do I owe you?" – "EUR 9,80")

– "Een slecht geweten": a guilty conscience. Lit.: a bad conscience.

Related words:
– Onschuldig: not guilty, innocent, harmless [adjective].

Example:
– "De ogen van een onschuldig kind maken de grootste bullebak week."
("The eyes of an innocent child weaken the biggest bully.")

– Schuld: guilt, debt [noun] [de schuld, de schulden].

sleeve
[noun]
[de mouw, de mou-wen]

A "mouw" is a sleeve. A "mouw" can be "kort" (short) of "lang" (long).

Examples:
– "Kijk! Er zit een lieveheersbeestje op je mouw!"
("Look! There is a ladybird on your sleeve!")

– "De mouwen van deze trui zijn te lang." 
("The sleeves of this sweater are too long.")

– "Hoe is het weer vandaag? Zal ik iets met korte of lange mouwen aantrekken?" 
("How’s the weather today? Shall I wear something with short or long sleeves?")

Expressions:
– "Daar valt wel een mouw aan te passen": we’ll manage somehow. Lit.: There’s probably a sleeve that can be adjusted.
– "Iemand iets op de mouw spelden": to tell someone a small (lie). Lit.: to pin something on one’s sleeve.
– "Uit de mouw schudden": to come up with something just like that. Lit.: to shake out of the sleeve.

Example:
– "Sander schudt moppen zo uit zijn mouw…echt grappig!"
("Sander comes up with jokes just like that…really funny!")

– "De handen uit de mouwen steken: to put one’s shoulder to the wheel. Lit.: to stick one’s hands out of the sleeves.
– "Daar komt de aap uit de mouw": the truth is revealed, the real intentions become clear. Literally: comes the monkey out of the sleeve.

Related words:
– Kort: short [adjective].
– Lang: long [adjective].
– Manchet: cuff [noun] [de manchet, de manchetten].
– T-shirt:T-shirt [noun] [het T-shirt, de T-shirts].
– Trui: sweater, jumper [noun] [de trui, de truien].
– Kleren: clothes [noun] [<no singular>, de kleren].

Extra:
Don’t confuse the noun "mouwen" (sleeves) with the verb "mauwen", which translates to "to meow" (the sound made by a cat), which also can be used figuratively: to whine. You may also see "miauwen", which also translates to "to meow", but which doesn’t have the figurative meaning.

toasted ham and cheese sandwich
[noun]
[de tos-ti, de tos-ti’s]

There’s not really an equivalent in English for “tosti”. In French, there is, though: “croque-monsieur”. “Tosti” apparently originates from the Italian “tosto” (from which “tosti” is the plural form), which is short for “tostato”, which is the past particple of “tostare”: to toast.
(Photo: Heather-D (flickr.com) – some rights reserved.)

A “tosti” is two slices of bread, by default with cheese and ham in between,
toasted all together. The ingredients may vary, but cheese (of any
kind) seems to be mandatory. If you order a tosti without further
specification, you will receive a ham and cheese tosti, mostly served with a small bowl of ketchup.

Examples:
– “Ik wil graag een tosti.”  – “Ham en kaas?” – “Ja, graag.”
(“I would like to have a tosti.” – “Ham and cheese?” – “Yes, please.”)

– “Lara maakt de allerbeste tosti’s!! Met Franse salami, tomaatjes en oude kaas…”
(“Lara makes the absolute best tostis!! With French salami, little tomatoes and old cheese…”)

– “Ober, mag ik mayonaise bij mijn tosti in plaats van ketchup?” – “Vanzelfsprekend, meneer.”
(“Waiter, can I have mayonaise with my tosti instead of ketchup?” – “Naturally, sir.”)

Related words:
– Tosti-apparaat: toaster device (for making tostis) [noun] [het tosti-apparaat, de tosti-apparaten].
– Tosti-ijzer: toaster device (for making tostis, lit.: tosti iron) [noun] [het tosti-ijzer, de tosti-ijzers].
– Broodrooster: toaster (for toasting slices of bread) [noun] [het broodrooster, de broodroosters].
– Roosteren: to toast [verb] [roosterde, geroosterd].

Extra:
You have a “broodrooster” (toaster) and a “tosti-apparaat/ijzer”. They are different devices. The former is a device used to toast bread, especially by exposure to electrically heated wire coils. The latter is a device for making tostis by heating/toasting a ham/cheese sandwich between two metal plates. These plates are usually heated electrically.