Silver, in J.R.R. Tolkien's words

The Quenya word for the metal silver is telpe.
The Sindarin word for the metal silver is celeb.

Silver, in my words

selgar : silver

The Illunse word for silver is selgar. Selgar is an unusual last name. Selgar is a place in Afghanistan.

This new word is a mashup of the Old English word for silver which is seolfor and the Latin word for silver which is argentum.

Brother, in J.R.R. Tolkien's words

The Quenya words for brother are toron (older source) or háno (later source and possibly a replacement of toron). In addition the word otorno means sworn brother or associate.

The Sindarin word for brother is muindor. In addition the word gwador means sworn brother or associate.

Bow, in J.R.R. Tolkien's words

The Quenya word for bow (weapon) is quinga.
The Sindarin word for bow (weapon) is peng.

I was careful translating the word bow to elven. Bow is one of those English words with multiple, diverse meanings. In addition to being a piece of resilient wood with taut cord used to shoot arrows, a bow can be the forward part of a vessel, a bending of the body as a sign of respect or acknowledgement or submission, a decorative interlacing of ribbons, and something curved in shape.

Wolf, in J.R.R. Tolkien's words

The Quenya words for wolf are ráca and narmo.
The Sindarin words for wolf are draug and garaf.

There are apparently two words for wolf in these Elven languages, which is interesting. I don't know how each word is used, or quite how they differ.

Dagger, in J.R.R. Tolkien's words

The Quenya word for dagger (or knife) is sicil
The Sindarin word for dagger (or knife) is sigil

For this English word the Quenya and Sindarin words are quite close. You might ask, what's the difference between the Elven languages of Quenya and Sindarin?

At the time of The Lord of the Rings, Quenya was no longer a living language: most Elves spoke Sindarin, and Men mostly spoke Westron. Quenya was used as a formal language and for writing; Sindarin was the vernacular Elven language. Tolkien occasionally referred to Quenya as "Elven-Latin".