Here's what you want to achieve using ConstraintLayout
<android.support.constraint.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:layout_width="match_parent"
android:layout_height="match_parent">
<TextView
android:id="@+id/email_label"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="EMAIL"
android:textSize="22sp"
app:layout_constraintLeft_toLeftOf="parent"
app:layout_constraintRight_toRightOf="parent"
app:layout_constraintTop_toTopOf="parent"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintVertical_bias="0.2" />
<EditText
android:id="@+id/email_input"
android:layout_width="0dp"
android:layout_height="50dp"
android:layout_margin="16dp"
android:background="@android:color/white"
app:layout_constraintLeft_toLeftOf="parent"
app:layout_constraintRight_toRightOf="parent"
app:layout_constraintTop_toBottomOf="@+id/email_label" />
<TextView
android:id="@+id/pwd_label"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginTop="40dp"
android:text="PWD"
android:textSize="22sp"
app:layout_constraintLeft_toLeftOf="parent"
app:layout_constraintRight_toRightOf="parent"
app:layout_constraintTop_toBottomOf="@+id/email_input" />
<EditText
android:id="@+id/pwd_input"
android:layout_width="0dp"
android:layout_height="50dp"
android:layout_margin="16dp"
android:background="@android:color/white"
app:layout_constraintLeft_toLeftOf="parent"
app:layout_constraintRight_toRightOf="parent"
app:layout_constraintTop_toBottomOf="@+id/pwd_label" />
<Button
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="LOGIN"
android:textSize="16sp"
android:layout_margin="16dp"
app:layout_constraintLeft_toLeftOf="parent"
app:layout_constraintRight_toRightOf="parent"
app:layout_constraintTop_toBottomOf="@+id/pwd_input" />
</android.support.constraint.ConstraintLayout>
In the email label's widget, You can also remove the "layout_constraintVertical_bias" and "layout_constraintBottom_toBottomOf" attributes and fix a top margin.
This can be done using Chains too.
Make sure you are using ConstraintLayout 1.0.2.
You can read this great tutorial about ConstraintLayout
Building interfaces with ConstraintLayout
Hope this helps!