Nominal Relative Clauses
In nominal relative clauses, the relative pronoun acts like a NOUN + RELATIVE PRONOUN TOGETHER.
I need a bed and IKEA had exactly what I was looking for. (=exactly the bed which I was looking for)

Nouns are one of the basic parts of speech and they refer to a person, animal, place, thing, phenomenon, substance, quality, or idea.
Nouns answer the questions "What is it?" and "Who is it?"

Adjective is a part of speech that modifies nouns and pronouns. Adjectives describe or give more information about nouns and pronouns.

There are two indefinite articles in English: a and an. Indefinite articles are invariable. You use one or the other, depending on the first letter of the word following the article. Use a when the next word starts with a consonant, or before words starting in u and eu (if they are pronounced with the consonant sound / j /). Use an when the next word starts with a vowel (a,e,i,o,u) or with a mute h.

Adverbs modify, or tell us more about, other words. Usually adverbs modify verbs, telling us how, how often, when, or where something was done and adjectives, making them stronger or weaker. The adverb is placed after the verb it modifies and before the adjective.

Review of Future Forms
Will/Shall (General Predictions)
Space tourism will become a reality.
Spanish will become the official language of the USA.
There will be unprecedented changes in the field of communications.

Zero conditional
Zero conditionals talk about things that are always true (e.g. scientific facts, habits)
In zero conditional both verbs are in the present simple

A prefix (affix) is a word, or letter(s) placed at the beginning of another word (a base word) to adjust or qualify its usage or meaning.
Understanding the meanings of the common prefixes can help us deduce the meanings of new words. This table defines and illustrates the most common prefixes.

With derivational suffixes, the new word has a new meaning, and is usually a different part of speech. But the new meaning is related to the old meaning - it is "derived" from the old meaning.

Defining relative clauses give essential information about a noun. Defining relative clauses are not put in commas.
My sister who lives in London is coming to Paris.