English Grammar 

I recently decided to finish my English language studies and earn a certification. It's been over three years since I last studied English, and most of what I know now is programming terminology.

I've started studying English grammar on my own, and this post will bring those notes together. I'll add five new topics each week, with links to online exercises.

My goal is to put together a complete guide that makes concepts easier to understand, even when they can be confusing in a classroom.

Indefinite Articles “a” and “an”

Spanish meaning

When to use "a" or "an"?

The meaning is the same; the difference is that we will use "a" when the word begins with a consonant sound and "an" when the pronunciation begins with a vowel sound.

Watch out for the "h"

If the word begins with "h", the indefinite article to be used will vary depending on the pronunciation.

Here are some words where the "h" is silent:

• honest
• honorable
• hour
• heir
• herb
• honor

When Not to Use the Indefinite Article

• Do not use a or an with uncountable nouns.
• Not used with plural nouns

Note: We can already see the importance of learning and practicing word pronunciation, which will come up throughout most of these topics.

Exercises

🔗 The Indefinite Article : English exercise.

🔗 Articles – Open Access Exercise

🔗 Indefinite Articles: A or An? - English grammar exercises

Plural

There are a few rules we can use to quickly know the plural of most words:

Irregular plurals

There are also irregular words that do not follow the rules above. Some examples are:

Exercises

🔗 Plurals – Free exercise

🔗 Noun Plural - English Grammar Exercises

🔗 Nouns : English exercise.

The Definite Article “the”

Spanish meaning

the => el / la / los / las

When to Use “the”

When Not to Use “the”

Pronunciation

Exercises

🔗 The Definite Article : English Exercise.

🔗 The Definite Article 2 : English Exercise.

Countable and Uncountable Nouns

Within the English language we can differentiate two types of nouns, countable and non-countable:

• water: not countable, you can't say "one water", "two waters"...
• house: countable, you can say "one house", "two houses"...

Key Differences

Examples of Uncountable Nouns

• wine
• water
• milk
• beer
• cheese
• fruit

Turning Uncountable Nouns into Countable Nouns

Many non-countable nouns can sometimes become countable nouns. However, their meaning changes:

• "wine" (non-countable noun) => wine is red
• "wine" (countable noun) => Sherry is a wine from Spain

In the second case, wine indicates a type of wine, not wine in general

• "hair" (countable noun) => hair / hairs means "pelo / pelos" in Spanish and refers to one or more individual hairs
• "hair" (uncountable noun) => refers to "cabello" in Spanish

Physical discomfort

Words for physical discomfort are compound words that end in "ache"

In Great Britain, the following are non-countable:

• I've got headache => tengo dolor de cabeza

In the United States, the following are considered countable nouns:

• I've got a headache => tengo dolor de cabeza

Demonstrative pronouns "This", "That", "These" and "Those"

That is a table > That's a table (more colloquial form)

Determiner

Demonstrative pronouns also function as determiners:

• Pronoun: replaces the noun => My opinion is this
• Determiner: accompanies the noun => I'm tired of these jeans

Exercises

🔗 Demonstrative Pronouns : English exercise.

🔗 Exercises: Demonstrative pronouns

The time

Key Concepts

Examples

Colloquial form

An easier and more colloquial way to tell the time is to read it as it appears on a digital clock:

Notes

• To ask the time we can say: "What time is it?"
• An easy way to remember past and to is with the Spanish word "pasto":
  • past → first half of the hour
  • to → second half

Exercises

🔗 Time : English exercise.

🔗 The Time – Free Access Exercise

🔗 Exercise 1 - The time in English

Ordinal numbers

Rules

Exceptions

Exceptions are like irregular verbs: there is no rule or pattern, so you just have to learn them.

Exercises

🔗 Ordinal Numbers : English exercise.

🔗 Ordinal numbers – Free exercise

The imperative

Generally, the imperative has the same form as the infinitive (to + verb), but without the "to".

Uses

Negative form

It is formed with don't + verb.
Example:
Don't do it! → ¡No lo hagas!

Emphasize More

To reinforce the imperative, the verb must be preceded by "do". This expresses emphasis or irritation.
Example:
Do turn it off! → ¡¡Apágalo!!

Use in instructions

When the imperative is used to give instructions, the verb can be in its infinitive form with "to", especially in educational or explanatory contexts.
Examples:
Listen to these words. → Escucha estas palabras.
Try to pronounce this word. → Intenta pronunciar esta palabra.

Exercises

🔗 Imperative Sentences : English exercise.

🔗 Imperative Sentences 2 : English exercise.

🔗 Imperative – Free exercise

The Saxon genitive

The Saxon genitive is used to denote possession in the following cases:

• People
• Pets
• Countries
• Expressions of time, space, or distance
• Sometimes, for cars and boats

It is also used with collective nouns that refer to organizations, companies or institutions, especially when referring to the people who work in them.

Examples:

• The hospital's room → La habitación del hospital
• The company's director → El director de la compañía

Structure

Possessor's name + 's + name of the object possessed

Examples:

• Susan's book → El libro de Susan
• Tom's grandmother → La abuela de Tom

Nouns ending in "s"

When the noun is plural and ends in "s", only the apostrophe (') is added.

Example:

• Two minutes' walk → Un paseo de dos minutos

Use in Time Expressions

Example:

• Have you got today's paper? → ¿Tienes el periódico de hoy?

Double Possessive

When there are two possessives (double Saxon genitive), the word order is reversed compared with Spanish.

Examples:

• This is John's mother's car. → Este es el coche de la madre de John
• Take Emily's sister's book, please. → Toma el libro de la hermana de Emily, por favor

Difference Between British and American English

The main difference lies in the use with collective nouns (restaurants, shops, schools, churches, etc.):

• British: requires the Saxon genitive with an apostrophe and "s". → St. Mary's School
• American: leaves the name unchanged, since possession is implied. → St. Mary School

Exercises

🔗 Exercises: Saxon Genitive

🔗 Exercise 1 - Saxon genitive in English - 1st ESO - Online English exercises

Personal pronouns in English

Subject pronouns

They are used to indicate who performs the action of the verb.

Example:

• I play soccer. → Yo juego fútbol.
• They study English. → Ellos estudian inglés.

Object pronouns

They are used when the pronoun receives the action of the verb or follows a preposition.

Example:

• I dance with her. → Yo bailo con ella.
• You talk to me. → Tú hablas conmigo.

Important Note

Don't confuse the subject pronouns with the object pronouns.
Although "you" and "it" are spelled the same in both cases, their function changes depending on their position in the sentence.

Example:

• You love me. → Tú me amas (you is the subject).
• I love you. → Yo te amo (you is the object).

Exercises

🔗 Personal pronouns: English exercise.

🔗 Exercises: Subject and object pronouns

🔗 Personal pronouns – Free exercise

Possessive adjectives in English

The possessive adjectives in English are words that indicate who owns something and are placed before the noun.

Examples:
My → mi, mis → My ticket = mi billete / My tickets = mis billetes
Your → tu, tus → Your house = tu casa / Your houses = tus casas

Features

• The order is the same as in Spanish: possessive adjective + noun.
• They do not distinguish between masculine and feminine.
• They do not change between singular and plural.
• Unlike Spanish, they agree with the possessor and not with the thing possessed.

List of possessive adjectives

Use with human body parts

In English, when talking about parts of the body, the possessive adjective is always used, and not the definite or indefinite article as in Spanish.

Example:
I've got a pain in my arm → Me duele el brazo.
(We do not say I've got a pain in the arm.)

Exercises

🔗 Possesive adjectives

🔗 Possessive adjectives and subject pronouns (I/my, you/your, etc.) - Test-English

Possessive pronouns in English

Example:
This is not my (possessive adjective) car. Is it yours (possessive pronoun)?

To understand possessive pronouns, it is very important to distinguish between a pronoun and a possessive adjective.

In the previous sentence, my is a possessive adjective because it comes before the noun car.
On the other hand, yours not only indicates possession, but also replaces the noun (car), which is understood from the context.
That is precisely a possessive pronoun.

Structure

The possessive pronouns (in English possessive pronouns) are formed, in most cases, by adding an "s" to the corresponding possessive adjective, as shown below:

Exceptions

The exceptions are:

• My, which becomes mine.
• His, which does not add an extra "s".
• Its, which has no possessive pronoun form, since it is not used to refer to the possession of things or animals without repeating the noun.

Exercises

🔗 Possessives: English exercise.

🔗 Possessive pronouns and determiners – Free exercise

🔗 Exercises - Possessive Adjectives and Possessive Pronouns

Reflexive Pronouns

The reflexive pronouns are used to indicate that the subject and the object of a sentence are the same person or thing, or to emphasize the subject.

They are formed by adding "self" (for singular) or "selves" (for plural) to the possessive adjectives.

List of Reflexive Pronouns

Note:

• Himself and themselves are formed from the object pronouns him and them.
• Itself has only one "s".

Characteristics of reflexive pronouns

Reflexive pronouns are usually accompanied by "by", and have the same meaning as expressions such as on my own (por mi cuenta, por mí mismo) or on his own (por su cuenta, por sí mismo).

Example:
We went to the cinema by ourselves → Fuimos al cine por nuestra cuenta.

When we want to reinforce the idea of doing it alone or without help, we add "all":

Did you do your homework all by yourself? → ¿Hiciste los deberes tú solo?

Other uses

Reflexive pronouns are also used to underline or emphasize the subject of the sentence.

Examples:
I've been to England myself → Yo mismo he estado en Inglaterra.
He likes to go running himself → A él mismo le gusta ir a correr.

Difference between reflexive and reciprocal sentences

In English, a distinction is made between reflexive sentences and reciprocal sentences.

Examples:

• Reflexive: John and Mary hate themselves when they fight.
  → John y Mary se odian a sí mismos cuando se pelean.
• Reciprocal: John and Mary hate each other when they fight.
  → John y Mary se odian el uno al otro cuando se pelean.

Note:
Each other is used for two people or things, while one another is used when there are more than two.

Example:
The four teammates hate one another → Los cuatro compañeros de equipo se odian entre ellos.

Exercises

🔗 Reflexive Pronouns : English exercise.

🔗 Reflexive Pronouns 2 : English exercise.

🔗 Reflexive pronouns – Free exercise

🔗 Exercises: Reflexive pronouns

Practice with AI

From this point, we will begin to study verb tenses, so I recommend doing mixed exercises that include sentences that use all the concepts covered above.
The objective is to strengthen the foundations of your understanding of the English language.

I also recommend using artificial intelligence with the following prompt:

"Make a list of 10 mixed multiple-choice exercises with sentences involving object pronouns, possessive adjectives, possessive pronouns, and reflexive pronouns."

Example:

Once you complete the exercises, ask for more and repeat them until you can consistently solve them correctly.

Remember that AI is a tool, and as such, it can still make mistakes. Don't be afraid to question it, ask questions, or correct it: it won't take it personally. Knowledge is free.

Introduction to Verb Tenses

In English, verb tenses indicate when the action occurs (present, past or future) and how it develops (whether it is a simple, continuous or perfect action).
Here's an overview of the three main types:

Simple Tenses

They are made up of a single verb, and in some cases, an auxiliary verb.
Example: I walk.

Continuous Tenses

They are formed with the verb "to be" (corresponding to Spanish "estar" here) plus the main verb in its -ing form.
Example: I'm walking.

Perfect Tenses

They are formed with the verb "to have" (corresponding to Spanish "haber" here) plus the main verb in its past participle form.
Example: I've walked.

Auxiliary Verbs in Simple Tenses

When we talk about auxiliary verbs in the simple tenses, we are mainly referring to "do" and its conjugations "does" (present) and "did" (past).
These are used to form negative and interrogative sentences.

Simple Tenses

The simple tenses are divided into present, past, future, and conditional, and each of them can be expressed in affirmative, negative and interrogative form.

Simple Present

• Affirmative: I walk
• Negative: I don't walk
• Interrogative: Do I walk?

Simple Past

• Affirmative: I was walking
• Negative: I wasn't walking
• Interrogative: Was I walking?

Simple Future

• Affirmative: I'll walk
• Negative: I won't walk
• Interrogative: Will I walk?

Simple Conditional

• Affirmative: I'd walk
• Negative: I wouldn't walk
• Interrogative: Would I walk?

Continuous Tenses

Continuous tenses are divided into present, past, future, and conditional, and each one has affirmative, negative and interrogative forms.

Structure

Continuous tenses are formed with:

• The conjugated form of the verb "to be" ("estar" in Spanish)
• The main verb in its -ing form

Present Continuous

• Affirmative: I'm walking
• Negative: I'm not walking
• Interrogative: Am I walking?

Past Continuous

• Affirmative: I was walking
• Negative: I wasn't walking
• Interrogative: Was I walking?

Future Continuous

• Affirmative: I'll be walking
• Negative: I won't be walking
• Interrogative: Will I be walking?

Conditional Continuous

• Affirmative: I'd be walking
• Negative: I wouldn't be walking
• Interrogative: Would I be walking?

Perfect Tenses

Perfect tenses are divided into present, past, future, and conditional, and each one has affirmative, negative and interrogative forms.

Structure

They are formed with:

• The conjugated form of the verb to have ("haber" in Spanish)
• The main verb in its past participle form

Present Perfect

• Affirmative: I've walked
• Negative: I haven't walked
• Interrogative: Have I walked?

Past Perfect

• Affirmative: I had walked
• Negative: I hadn't walked
• Interrogative: Had I walked?

Future Perfect

• Affirmative: I'll have walked
• Negative: I won't have walked
• Interrogative: Will I have walked?

Conditional Perfect

• Affirmative: I would have walked
• Negative: I wouldn't have walked
• Interrogative: Would I have walked?

The verb "to be"

The verb to be corresponds to both "ser" and "estar" in Spanish.
It is used to describe characteristics, states, identities, professions, places and more.

Affirmative Form

Negative formation

Interrogative Form

(It has no contraction)

Exercises

🔗 To Be : English exercise.

🔗 To Be 2 : English exercise.

🔗 Exercises: 'To be' - Simple present

The verb "to have"

The verb to have corresponds to "tener" and "haber" in Spanish.
It is used to express possession ("tener") and to form the perfect tenses in English ("haber").

Affirmative Form

Negative formation

Interrogative form

(It has no contraction)

Important Note

The conjugation we have just seen is the one used for the perfect tenses in English (present perfect, past perfect, future perfect, etc.).

However, the conjugation of "to have" to express "tener" in the sense of everyday possession is explained in the next section.

Other verbs

For all verbs except modal verbs (can, could, must, have to, might, may, should), these rules apply.
We will use the verb to walk (caminar) as an example.

Affirmative form

(It has no contraction)

Negative form

Interrogative form

(It has no contraction)

Exercises

🔗 Exercises of Simple present affirmative with 'To have'

🔗 Exercises: 'To have'

🔗Verb "To have" - Exercises - English A1

Glossary

Consonant

They are alphabet sounds that are pronounced by blocking the air with the tongue, lips, or teeth.

• Examples: B, C, D, F, G, H, J, K, L, M...

Vowel

These are sounds that are produced by letting the air out freely, without blocking it.

• In English (and Spanish) they are: A, E, I, O, U

Noun

It is a word that names a person, place, thing or idea.

• Examples: dog, teacher, city, love

Pronoun

It is a word that replaces a noun so as not to repeat it.

• Examples: he, she, it, we, they

Prompt

A prompt is an instruction, order, or input given to an AI tool to generate a response.

Author's Note

Writing this grammar compilation has been very rewarding for me. However, for several reasons, it is currently very difficult for me to keep up with five topics a week. I'm putting this post on hold for now (June 2026), as my time and attention are focused on other projects. I will still gradually review what has already been covered and try to improve how the information is organized and make it more accessible, using tools such as diagrams, tables and text-to-speech.

Also, I hope to return to this post toward the end of this year. Once I finish it, I plan to start a new one focused on algebra and calculus.